It is called a fuel pump because that's exactly what it does. The pulse line provides pulsing on a diaphragm which in turn sucks and pushes the fuel through two one way valves. It sucks from the tank through a one way and then pushes through another one way to the carb
My 97 scrambler came without the pump. Someone made it gravity fed. It dont like to start so im replacing the pump and lines so im thankful for this video.
This sounds like what I might need to do on my Trail boss 325. I've been racking my brain trying to figure out why mine is sputtering and almost dying while accelerating. Must have had the carburetor off 8 times and cleaned it.
Finally someone explained how a fuel pump worked without power going to it. I heard about how quiet it was when you turned the key on and was pumping gas.
thanks Dustin I'm definitely going to replace the fuel pump and replace all the fuel line. I'll let you know how it all works out. I sure hope it does it's been a couple years since we've got to enjoy it. thanks again.
Dustin Elgan feeling a little down, I put a new fuel pump and replaced all the fuel lines but still won't run. Will only run til it burns off the starting fluid I spray in it. We can keep it sputtering for about maybe 10 seconds or so by feathering the throttle. Do I have a problem with the carb.? Fuel was leaking from petcock when I was putting it back together. Seemed to be ok when I checked it like you showed in your video.don't know what to do...
Great video! I’m doing a restoration for a friend on a trail boss 330 and based in their description of the issues I think you nailed the solution on this vid so I’m pumped to dive into her in a couple days. Thank you!!!
This is one of the best videos on repairing the fuel system on a quad! I have several ATVs of different makes and hp for every member of the family. Some easier to work on than others and the Trail Boss is one of the worst. I had the same problems with my Trail Boss and this video was so detailed that I never got the manual out. I think it was especially important to note that you might as well replace the fuel lines. How true; rerouting old, stiff lines and trying to twist the components back into shape is just asking for more trouble. The Boss is now working great after doing through all the steps and replacing all the comments (including the fuel pump) as shown in this video. Well done!
I’m not sure if the fuel pump is my issue but the other day I was riding my 97 425 magnum with no issues no sputter no nothing but then the strangest thing is happening I ran out of gas so I filled it back up and now it won’t run unless the choke is on but it can only idle , as soon as you hit the gas with the choke off or on it dies
I have an 02 sportsman 500 HO and have had fuel issues for ever it seems. It has the same so-called fuel pump as the one in video. I tried bypassing it to no avail, wouldn't run. Mine is located under the left front fender where it gets plenty of mud. In dissecting it one day I discovered 3 tiny weep holes in the back "air chamber" that were clogged with dirt. After I cleaned it up and reinstalled it, it's pulling fuel like it should again. So if you have a similar pump, before replacing it, check those little holes. May end your issue.
This seems like such an easy fix, mine surely can't be this - Scrambler 500, has spark, compression, seems to get fuel - doesn't run, backfires occasionally while cranking. I've checked most everything out, cam lobes are good, even bought a new carb. I guess I'll replace the fuel line. Edit - I bought a new fuel pump also, still didn't help
This is funny, I had the same problem, but I had to change the carb, but I had a buddy put in a gas filter and change out some things like the nob for the gas.
Spudnick MORTY glad you fixed it. Sometimes a clogged filter is enough to make things run bad by itself, those carbs aren't cheap! Thanks for your comment.
Dustin Elgan hey I have a trail boss 350 and I was coasting down a hill and it died and sputtered out and have not been able to run Sence could u give me some advice on how to fix it also I just premixed gas instead of using the oil tank did that mess anything up or not
I think my carb isn’t making vacuum, when I leave my pressure line hooked into the carb and blow into it I can’t hear an air leak and whatever the vacuum needle thing is doesn’t move in the carb, can anyone help?
😅 my good guess man , na really tho P , pulse , aka vacuum to a diaphragm pump , a larger example of a chain saw or weed Wacker , pulls on the diaphragm and releases it therefore creating an pull as Long as there no leaking lines to lose said vacuum it splits at the petcock located in the frame near the fuel outlets on the bottom of the tank, (wish the petcock was on the Tank
You had the fittings explanation backwards. The long one with the plastic is for reserve and the plastic part holds a small amount of extra gas that it will run off of when reserve is selected
Doctor Feinstone thanks for your comment. I rewatched my video and my explanation is actually correct. The longer nipple fitting with plastic tube is the “fuel on” fitting. The “reserve fuel” fitting is the short one. The plastic is to keep reserve fuel in the tank, not reserve fuel in the plastic sleeve (quad would only run for seconds on fuel inside that sleeve if I’m understanding your comment right, that’s not what I’d call a reserve). The black plastic piece determines the height that the filter draws fuel from to keep a reserve in the bottom of the tank so you don’t unknowingly empty your tank while riding. That longer nipple only has access to 80% of the fuel in the tank, so it’s not the reserve, it’s “fuel on”. The shorter sleeve sucks from the bottom of the tank (it has 100% access to all fuel because it’s short and sits at bottom of the tank, thus it’s the reserve nipple). You switch from “fuel on” to “reserve” when your quad sputters when fuel level drops below the plastic sleeve so you know you’re getting low. I hope this explanation makes sense to you.
No problem, I went through the same thing, thus the video. See on my channel the other fuel pump video bypass to verify your carb and engine aren't the problem. Best of luck, let me know if you have any questions I'll gladly talk you through it.
Dustin please tell me where that little hose goes that's coming off the top of the gas tank? There's also another one coming from the instrument cluster. I can't figure out where they go to. Thanks for your help!
its a fuel pump that works with vacuum it has a rubber bladder inside every time your piston moves it creates a suction so it can pump fuel into the carb
Actually its a pulse signal that does have a positive and negative signal from piston.. up and down.. fuel pump has a check in it that, is crucial to the operation of unit.. no its not a direct vacuum that makes it work .. must be a pulse signal.... Jose there is more to it..
I just did the same fuel line replacement on mine and went ahead and cleaned the whole carb out as well. Now I have a whole new problem - it seems to be starving for air with any attempt to rev the engine. With the airbox off I can see into the air intake and nothing is opening up with throttle pressure so I may have an issue with some aspect of the jet needle reassembly ....taking her apart again
Todd Staples hey, sorry you’re having problems. You say you’re not getting enough air? Did you check your nipples in the fuel tank? You might be starving for fuel. I’ve seen the sock filters on end of nipples get plugged up. I hope that helps you, check your fuel pump too. They are cheap and not terrible to replace. Best of luck, thanks for your comment
yeah when I replaced all the lines I blew everything out and cleaned the tank too so I am confident that it is getting fuel. When I do rev it up it literally sounds like it is choking on fuel and the smell of unburnt gas is strong in the exhaust. I didn't change anything else as far as adjustments go. It was running good before I replaced everything other than occasionally having issues starting cold which prompted me to do the clean up. Thanks for the response Dustin.
Todd Staples unburnt fuel means an overly rich mixture, you obviously already know that, I’m not trying to be preachy or anything, just trying to help you get to bottom of problem. Good news is you are getting fuel, right 👍. That’s usually half the battle. If you can rev up the quad it isn’t an air issue unless you have something restricting the air which in most cases you can see pretty quickly. From my experience my money is on Your needle and seat/float not be seating properly after your tear down or you accidentally bent the adjustment tab for the float making it not close the needle and seat all the way when it’s full. All it takes is a little dirt or varnish to compromise its ability to meter the fuel going into the carb/engine. Does quad leak fuel overnight if you leave the fuel petcock valve on? That would be a way of checking for fuel float/valve and seat issues without tearing into anything. You may have stirred up varnish and clogged a port also. Do you have a fouled spark plug? Could be another possible issue, not burning all the fuel, but quad wouldn’t start very well (if at all) if that was the case. Let me know if you figure it out, would love to know how you made out. Thanks for your comment again, I wish you the best.
I suspect you are right on the floats or maybe the adjustment tab you mentioned. It's weird it almost acts like it is running with the choke on all the time. I'm tearing it apart now so I hope to have an answer soon. Nothing leaks and I keep the valve open all the time - this quad is my workhorse and usually is attached to a cart that I use to move firewood and other stuff so it sits outside 24/7. Thanks for all the great tips! Let me know if you know how to detatch the choke cable from the carb? Last time I disassembled this I remember having an issue getting the choke off as it seemed to be held in place by something inside the carb.
Todd Staples yeah, never messed with my carb unfortunately, never had to luckily. I have torn into my Yamaha and the kids Tao Tao quads, this linkage attachments can be a little tricky. Maybe you’re choke cable got preloaded when everything got reassembled keeping your choke on all the time. If your choke is sane as mine, it’s tough to say if it’s attached right or not.
Will the 325 trail boss run right if I bypass the fuel pump and run a line of gas directly to the carb? Also do you have any videos on that vacuum box that's mounted on the head? Not sure what that box actually does. Thanks and keep up the good work.
Jason Day I remember that the quad ran ok with direct feed gas, but I put a new fuel pump in regardless and it runs a little better. I don’t see how bypassing the fuel pump would cause any issues and may increase reliability though my quad idled better with the new fuel pump. As for the vacuum box you inquired of, I believe that is the crankcase breather. Not much to really say about it other than that line connects back in with the air filter box on the fwd side when you reinstall everything to put the quad back on the trail. Hope this helps. Best of luck to ya, thanks for the comment. 👍
Im having issues with my 01 325 trail boss. It will start with the pull start and run like junk. Will not excellerate at all. No funny noises from the engine so i assume its a fuel issue. I cleaned the carb. Changed the plug and end. Drained lines and added fresh fuel. Changed nothing. Please help.
Bob Disandro follow my tutorial for fuel pump fix. Either bypass the pump or replace it, consider replacing all of your fuel lines, they can collapse internally and restrict fuel flow. Hope this helps you.
sometimes its not necessarily the fuel...if it is an older model quad and driven a lot it could be a worn cam lobe. Polaris engines are notorious for worn cams.
Hi dustin,i have the same atv,i took carb off cleaned it really well but there is a flat head screw at bottom next tothe float,it has a spring on it. How many turns does it need to be when putting it back? PLEASE CAN YOU HELP ME? thank you
1982pantro that’s likely your fuel air mixture screw. Screw it all the way in, then count the rotation out at 1 &1/2 turns. That’s a good starting point for adjusting the carburetor. I’m sure there are videos on CZcams that will give you tips on getting the carb fine tuned, if it runs good like that you shouldn’t have any problems. Thanks for your comment and best of luck to you.
Find the line going to the shorter filter going into your tank, plug the other outlet and run the hose that connects to the center connector on your petcock valve to the short filter outlet on bottom of your tank
Dustin. 2005 Polaris Sportsman 400 appears to operate a very similar system. There is a small plastic line that leaves the top of the fuel tank (through a nipple on the top) and appears to go up into the instrument panel at the top front of the quad. What is that line and what if it is cracked or broken? Also how difficult to replace? Thanks
Ted Wheat that’s your tank vent line, in order for fuel to flow you need to displace fuel with air in your tank as you use the fuel or it will not flow freely. Not a terrible job to replace, just remove the fairings/plastics around the tank and you should have access to replace the line. Worse case scenario you may have to remove the tank to get access to the line. Just replace it with fuel resistant hose from Autoparts store or small engine repair shop. Best of luck to you, thanks for your comment, hope this helps.
I did a full carb rebuild, fuel pump was changed, ran the fuel lines to the proper places and changed the plug. it starts up fine and will idle but the moment i hit the throttle when the quad is in gear it dies out. i tried adjusting the throttle cable but it still does the same thing. my only other thought would be that i used a lower octane fuel to see if it would even run after all the work. could this be a factor or should i look into something else??
Brian Cushler did you adjust the float in the carb? Sounds like you don’t have enough reserve fuel for when you demand more. That’s a possibility, but I’ve never messed with that particular carb. There should be a air/fuel mixture screw that would help you too, you could be running her lean. Did you clean the fuel strainers that connect to the lower nipples that provide fuel from the tank? I don’t feel that lower octane fuel is the cause unless you’re running absolutely old garbage gas, which in that case you’d idle rough if at all. Let me know if this helps.
I'm in the process of chasing down a fuel issue of my own on my Sportsman 700. I replaced the carb and still have issues. So tomorrow I am removing everything and replacing the petcock, pump and all the lines. I was going to try to clean the tank as well. But I'm curious as to how the nipples on the tank come out and go back in? I'm a little nervous about breaking a seal and having a future leak. So my question is, how do they come out and have you had any issues with them after removing them? Thanks!
Mike Boley they thread into the plastic and they seal up fine, nothing to worry about, don't over tighten them. Brass will always win over plastic when torque is in play. Just make sure you take note on which nipple fitting is reserve and which one is the on position so you correctly connect the lines to your petcock valve, my only recommendation for you if you're going for a full fuel system rebuild. I hope my video is of help to you and thanks for your comment. Best of luck with your sportsman 700
Dustin Elgan thank you so much! Where did you get your fuel lines? I was going to try to go to the parts store but someone said the last time they went there they said they weren't allowed to sell him the lines by the foot. They ended up just cutting him a section and gave it to him. Not sure what that was about, but I may have to go online to buy them. Thanks again!
Mike Boley got my lines at advance auto. If any of the big store brands say no, you can't go wrong going to a Napa or other smaller name Autoparts stores. They'll accommodate you better for sure. There's always eBay and amazon as well, you'll need like 7' of 1/4" fuel line I believe, all that info is in the video. Online will probably be cheaper TBH. Best of luck, let me know how you make out.
Bob Disandro see my tutorial on headlight starter switch replacement on my channel. This may help you. If that doesn't work check your stater solenoid just forward of your battery. If nothing after that replace your starter and make sure there's no corrosion on battery cable terminals or faulty cables. Hope this helps you.
Hi do you still have this four wheeler and would you be able to help me with finding the wiring I need to get this running? I bought one that needed a cdi box and I have that now but I can not find where the other wires go
please help me....my trail boss 330 loss fuel for the fuel shut off petcock.....but only one line come to the gas tank at the petcock.....the other 2 holes of the petcock are empties ....its correct??? only one line of the gas tank comes at the petcock?? thanks
madsen madsen there should be 2 fuel lines coming from your tank unless someone changed your setup. So, two lines come from tank to either side of the petcock valve, one line goes from petcock to your fuel pump or to your carburetor if you choose to bypass the fuel pump. If you lost fuel to your carb, I'd start by checking the routing of your fuel lines and also check to see if your fuel lines are compromised/old/collapsed in on themselves affecting fuel flow. Next, pull a fuel line from the tank to see if fuel flows freely by gravity from tank, check to see tank vent isn't clogged, check this by opening fuel cap, if fuel flows better then you'll know it's a venting issue. Next check for clogged screens at fuel nipples in tank, check for clog at petcock valve and fuel pump, then if this doesn't fix the issue check your carburetor bowl and float for a stuck needle and seat. I hope this helps. Let me know how you make out.
Sounds like your float is stuck, gas shouldn’t be burping out of your carb. Take carb off, disassemble it and check your needle and float. Your float is either damaged and doesn’t float anymore or your needle and seat is compromised or dirty.
Thanks but I finally figured it out ... the skirt on the intake side of piston broke off lol. Last thing I ever would of thought. Good news I'm a certified polaris technician bc I went through every fucken thing on it lol
Technically, the "P" line IS pressure. Negative pressure, which is also called VACUUM. Negative pressure, also known as a vacuum, is a process that reduces the air pressure inside a container to a level that is lower than the outside atmospheric pressure. @@dustinelgan6070
Sam Remy check your carburetor, sounds like your needle and seat isn't closing all the way in the float bowl. Hope this helps. Let me know how you make out.
I have a 400 sportsman 2002 put a new cam in got everything rite now it will run but like crap sometimes it will take off good then it will go like crap then it will idle high then die then start it up and all the same again I need help
Randy Kuball sounds like an electrical issue, check all your connections being that it was all taken apart for the rebuild. It obviously isn’t a mechanical issue or there would be other symptoms. I doubt it to be a fuel issue unless your carburetor was messed with or has clogged insides. I’m leaning towards electrical though. Start simple and troubleshoot from there. Hope this helps you.
Hi i have a Polaris Trail boss 325 and when i start it up and go to put it Forward or Reveres it makes a Grinding sound and shuts off!! I tried pressing the Gas and then putting it in Forward and it works!! But when i hit the brakes it shuts off! Anyone know what to do? We think the clutch is stuck!!Plz help!!!
Colton Bocock start by removing the clutch cover and see what’s going on. With machine off that belt should be loose enough to move with your hand. If the belt is tight and the primary clutch is full diameter, then you have a seized primary clutch. They can be rebuilt but you should also look at your clutch covers and see if you are getting water and debris in there. They are supposed to be relatively water tight to keep stuff from binding and wearing out your clutches and belt.
cody h start with a Polaris parts dealer and go from there, I’m pretty sure there’s some aftermarket stuff out there, but I haven’t looked. If you find something please share it so we can help others as they fix their machines.
I prefer to disable the fuel pump and go directly to the carb from the tank.. the fuel pump operates by pulsation created by rpm from motor. the fuel pump only pumps fuel at high rpm. it will not pump at idle thus using up the fuel that is left in the bowl. watch your fuel filter at idle and you will see it empty out...rev the motor and the filter will fill back. This draw back of fuel can cause a rough idle and rpm take off. I consider these pumps useless seeing as how gravity feed serves best with a constant flow.......(my opinion and i'm sticking to it)
limbslapper one yeah, I see what you mean, makes sense that the pump works when you rev it because of the vacuum line running to the pump. I ran my quad bypassed and connected to the pump, I found mine ran a little better and had a small noticeable amount more power with the pump connected. There’s lots of variables between everyones machines, I was hoping that it would run better bypassed TBH, but mine preferred it. Thanks for your comment, I love the feedback that I get on these topics.
madsen madsen I checked out your forum and that trailboss was really poorly maintained, you inherited a basket case. Don't worry, my trailboss wasn't much better when I bought it, just see my channel and you'll see some of the fixes that I documented. My fuel tank had mulch and dirt in it lol. I suggest you fix that pull start sooner than later, the pull start handle acts as a cap to keep water and dirt from entering into that case. I have to fix my pull start as well because the retract stopped working. Your petcock valve is definitely broken and not connected properly. The two lines you mentioned coming from the carburetor to the fuel pump in your forum is correct, one line going to the CVT belt side/petcock/LH side of your quad to your carburetor is your fuel feed, the line opposite/exhaust pipe/RH side of carburetor is a pressure/vacuum line that makes your fuel pump function. Whoever had your quad before bypassed the petcock valve which is ok, I wouldn't worry about it now, it's functional that way. The single line going to your petcock valve may be coming from your reserve or fuel on nipple from your tank because it has nowhere else to go if I had to guess. If you're not getting fuel to the carb, run a fuel line directly from your tank to the fuel inlet on your carb to troubleshoot if your fuel pump is working or not. Don't worry about disconnecting the vacuum line to test this. If your quad runs with this setup then know you have a faulty fuel pump. I did another video on how to do this bypass, check my channel. Hope this helps you out.
madsen madsen the line going to the petcock, take it off and plug it. It's doing nothing for you, just leaking all over the place. That valve is to allow you to run your quad with the option of having a reserve when you run low on fuel when put in the on position. Right now that valve is bypassed and that valve has one of the two fuel lines ran to the valve acting as a plug that could be opened, really a bad unsafe way of plugging the line.
The fuel system as it is set up with this quad takes a little bit to run the air out of the 4-5' of hose from where the gas enters to where it finally gets to the carb. I'm going to ask you some questions and hopefully I can help troubleshoot the issue with you. It's a frustrating system, I'll add in a few tips that helped me. Feel free to email me your number if none of this works and I'll gladly call you and talk with you if you'd like, versia23@hotmail.com. Do you have a clear fuel filter like I have going to the fuel pump to see flow? Did you check your nipple fittings coming from your tank to see if mesh screens are not clogged? Is your tank properly vented to allow fuel to flow in that system? I blew into the tank once to push the fuel through the system, you can try that. Does the pressure line allow the pump to work, vacuum leak issues with carburetor anywhere? Is your needle and seat for your carb potentially sticking in float bowl? Try disconnecting fuel feed line going into carb, hold line in container, run the quad on starting fluid and see if fuel primes your line that way. If it does fuel will flow of nothing else is compromising your system. Check that all your lines are hooked up right. If that doesn't work, bypass the fuel pump as described in my other video and see if the quad will run. If it still doesn't run, and you can't get fuel from your tank to the carb, then take your tank off and investigate. Clean out your tank, put in fresh 93 octane fuel. Check for pinched fuel lines, replace all fuel lines of not already done so, push compressed air through lines (not through new fuel pump). Fuel should readily flow by gravity from tank without assistance. Once fuel flow, fuel lines and petcock are out of the possibility of being compromised, it's time to look at the carburetor float system and vacuum system to see if they are compromised. Let me know if any of this helps.
Hey dustin I took the fuel line that feeds into the carb used starting fluid and tried a few times. first off a reddish colored liquid came out then it cleared up but it still won't run. if I pull the choke I can keep it going for a little bit but it still won't run. I'll e-mail you my number and maybe we can solve this. do I need to pull the carb off.? I replaced all the fuel lines and pump so I don't know where that nasty red liquid came from since that was before the carb. well any thoughts.?
It is called a fuel pump because that's exactly what it does. The pulse line provides pulsing on a diaphragm which in turn sucks and pushes the fuel through two one way valves. It sucks from the tank through a one way and then pushes through another one way to the carb
My 97 scrambler came without the pump. Someone made it gravity fed. It dont like to start so im replacing the pump and lines so im thankful for this video.
It's a pulse and it pulls and let's up on the diaphragm and makes a pump situation at low pressure nearly gravity but it works
This sounds like what I might need to do on my Trail boss 325. I've been racking my brain trying to figure out why mine is sputtering and almost dying while accelerating. Must have had the carburetor off 8 times and cleaned it.
Def follow my video, it’ll help out a ton. Maintenance items that generally get overlooked and typically you find where previous owners went wrong.
appreciate you. the fuel line diagram is what i was needing clarification on, had 2 lines mixed up and you solved my issue.
Thank you young man! I just got two 325’s 01’s. And that helped me a lot thank you
Thanks a million dude. Helped me save my 96 polaris magnum 425. Much appreciated.
What was yours doing?
Thanks for your feedback, much appreciated
This helped me in 2 mins thank my quad runs now and does not poor gas from the exshaust
Andrew Mcdougal that’s awesome! So glad it helped you. Thanks for the comment.
Finally someone explained how a fuel pump worked without power going to it. I heard about how quiet it was when you turned the key on and was pumping gas.
was totally lost until I watched this thank you man same setup on the sportsman 335
Product review glad I could help! Best of luck to ya.
@@dustinelgan6070 it´s exactly th same for my Polaris Magnum 425 !!. thabk you very much. i just subscribed and liked the video. (y)
thanks Dustin I'm definitely going to replace the fuel pump and replace all the fuel line. I'll let you know how it all works out. I sure hope it does it's been a couple years since we've got to enjoy it. thanks again.
Let me know how you make out. Thanks for watching and for subscribing! Best of luck👍
Dustin Elgan feeling a little down, I put a new fuel pump and replaced all the fuel lines but still won't run. Will only run til it burns off the starting fluid I spray in it. We can keep it sputtering for about maybe 10 seconds or so by feathering the throttle. Do I have a problem with the carb.? Fuel was leaking from petcock when I was putting it back together. Seemed to be ok when I checked it like you showed in your video.don't know what to do...
maybe a carb needle problem ?
Great video! I’m doing a restoration for a friend on a trail boss 330 and based in their description of the issues I think you nailed the solution on this vid so I’m pumped to dive into her in a couple days. Thank you!!!
Saint Revenga you’re welcome. Thanks for your comment, best of luck with your project
We recently got a 300 sportsman and we have a 330 carburetor put on incorrectly. The man mixed tho hoses up and we need some help @dustinelgan
great walkthrough. appreciate the details.
Excellent video for beginners like me-thank you!
This is one of the best videos on repairing the fuel system on a quad! I have several ATVs of different makes and hp for every member of the family. Some easier to work on than others and the Trail Boss is one of the worst. I had the same problems with my Trail Boss and this video was so detailed that I never got the manual out. I think it was especially important to note that you might as well replace the fuel lines. How true; rerouting old, stiff lines and trying to twist the components back into shape is just asking for more trouble. The Boss is now working great after doing through all the steps and replacing all the comments (including the fuel pump) as shown in this video. Well done!
I’m not sure if the fuel pump is my issue but the other day I was riding my 97 425 magnum with no issues no sputter no nothing but then the strangest thing is happening I ran out of gas so I filled it back up and now it won’t run unless the choke is on but it can only idle , as soon as you hit the gas with the choke off or on it dies
puchski1 thanks for the positive comment. I really appreciate it
Extremely helpful. Thanks for posting this.
It's actually a pump. The pulse from the engine works the diaphragm and pumps fuel.
you helped me within the first two minutes. very informative!! thank you so much.
Low Budget Garage glad I helped. Best of luck, thanks for the comment.
Mine was the carburetor. I replaced carburetor and woks great.
I'd consider it a fuel pump, it pulls gas up instead of gravity fed, they do have some pressure
Thank you very much for this great video turorial!
I have an 02 sportsman 500 HO and have had fuel issues for ever it seems. It has the same so-called fuel pump as the one in video. I tried bypassing it to no avail, wouldn't run. Mine is located under the left front fender where it gets plenty of mud. In dissecting it one day I discovered 3 tiny weep holes in the back "air chamber" that were clogged with dirt. After I cleaned it up and reinstalled it, it's pulling fuel like it should again. So if you have a similar pump, before replacing it, check those little holes. May end your issue.
George Douglas thanks for your comment. That is helpful info to anybody dealing with Polaris fuel ailments.
thank you.
You're welcome😊
Thanks
This seems like such an easy fix, mine surely can't be this - Scrambler 500, has spark, compression, seems to get fuel - doesn't run, backfires occasionally while cranking. I've checked most everything out, cam lobes are good, even bought a new carb. I guess I'll replace the fuel line. Edit - I bought a new fuel pump also, still didn't help
Cdi
This is funny, I had the same problem, but I had to change the carb, but I had a buddy put in a gas filter and change out some things like the nob for the gas.
Spudnick MORTY glad you fixed it. Sometimes a clogged filter is enough to make things run bad by itself, those carbs aren't cheap! Thanks for your comment.
Dustin Elgan hey I have a trail boss 350 and I was coasting down a hill and it died and sputtered out and have not been able to run Sence could u give me some advice on how to fix it also I just premixed gas instead of using the oil tank did that mess anything up or not
I think my carb isn’t making vacuum, when I leave my pressure line hooked into the carb and blow into it I can’t hear an air leak and whatever the vacuum needle thing is doesn’t move in the carb, can anyone help?
Sounds like an internal issue with your carburetor. If you’ve already taken it apart, check your seals for leaks
😅 my good guess man , na really tho P , pulse , aka vacuum to a diaphragm pump , a larger example of a chain saw or weed Wacker , pulls on the diaphragm and releases it therefore creating an pull as Long as there no leaking lines to lose said vacuum it splits at the petcock located in the frame near the fuel outlets on the bottom of the tank, (wish the petcock was on the Tank
You had the fittings explanation backwards. The long one with the plastic is for reserve and the plastic part holds a small amount of extra gas that it will run off of when reserve is selected
Doctor Feinstone thanks for your comment. I rewatched my video and my explanation is actually correct. The longer nipple fitting with plastic tube is the “fuel on” fitting. The “reserve fuel” fitting is the short one. The plastic is to keep reserve fuel in the tank, not reserve fuel in the plastic sleeve (quad would only run for seconds on fuel inside that sleeve if I’m understanding your comment right, that’s not what I’d call a reserve). The black plastic piece determines the height that the filter draws fuel from to keep a reserve in the bottom of the tank so you don’t unknowingly empty your tank while riding. That longer nipple only has access to 80% of the fuel in the tank, so it’s not the reserve, it’s “fuel on”.
The shorter sleeve sucks from the bottom of the tank (it has 100% access to all fuel because it’s short and sits at bottom of the tank, thus it’s the reserve nipple). You switch from “fuel on” to “reserve” when your quad sputters when fuel level drops below the plastic sleeve so you know you’re getting low. I hope this explanation makes sense to you.
Ok that’s cool but where does the lines to the tank n peacock go
Informative..Thanks
Thanks for the vid, i have a 335 sportsman ive been going crazy on it and going to try this idea thanks again!
No problem, I went through the same thing, thus the video. See on my channel the other fuel pump video bypass to verify your carb and engine aren't the problem. Best of luck, let me know if you have any questions I'll gladly talk you through it.
At the top of the carb there's a nipple is that for vent for the diaphragm inside the carb?
Dustin please tell me where that little hose goes that's coming off the top of the gas tank? There's also another one coming from the instrument cluster. I can't figure out where they go to. Thanks for your help!
OK thanks bro thought vent also appreciate it :)
its a fuel pump that works with vacuum it has a rubber bladder inside every time your piston moves it creates a suction so it can pump fuel into the carb
jose flores thanks for your comment, I figured that's how it worked by design, you just confirmed it. Thanks again.
Actually its a pulse signal that does have a positive and negative signal from piston.. up and down.. fuel pump has a check in it that, is crucial to the operation of unit.. no its not a direct vacuum that makes it work .. must be a pulse signal.... Jose there is more to it..
No wires! Jose is correct. He explained it very well.
Very helpful thank you 🙏
Br0sph 2.1 you’re very welcome. Thanks for the comment
Nice 👍
I just did the same fuel line replacement on mine and went ahead and cleaned the whole carb out as well. Now I have a whole new problem - it seems to be starving for air with any attempt to rev the engine. With the airbox off I can see into the air intake and nothing is opening up with throttle pressure so I may have an issue with some aspect of the jet needle reassembly ....taking her apart again
Todd Staples hey, sorry you’re having problems. You say you’re not getting enough air? Did you check your nipples in the fuel tank? You might be starving for fuel. I’ve seen the sock filters on end of nipples get plugged up. I hope that helps you, check your fuel pump too. They are cheap and not terrible to replace. Best of luck, thanks for your comment
yeah when I replaced all the lines I blew everything out and cleaned the tank too so I am confident that it is getting fuel. When I do rev it up it literally sounds like it is choking on fuel and the smell of unburnt gas is strong in the exhaust. I didn't change anything else as far as adjustments go. It was running good before I replaced everything other than occasionally having issues starting cold which prompted me to do the clean up. Thanks for the response Dustin.
Todd Staples unburnt fuel means an overly rich mixture, you obviously already know that, I’m not trying to be preachy or anything, just trying to help you get to bottom of problem. Good news is you are getting fuel, right 👍. That’s usually half the battle. If you can rev up the quad it isn’t an air issue unless you have something restricting the air which in most cases you can see pretty quickly.
From my experience my money is on Your needle and seat/float not be seating properly after your tear down or you accidentally bent the adjustment tab for the float making it not close the needle and seat all the way when it’s full. All it takes is a little dirt or varnish to compromise its ability to meter the fuel going into the carb/engine.
Does quad leak fuel overnight if you leave the fuel petcock valve on? That would be a way of checking for fuel float/valve and seat issues without tearing into anything.
You may have stirred up varnish and clogged a port also.
Do you have a fouled spark plug? Could be another possible issue, not burning all the fuel, but quad wouldn’t start very well (if at all) if that was the case.
Let me know if you figure it out, would love to know how you made out. Thanks for your comment again, I wish you the best.
I suspect you are right on the floats or maybe the adjustment tab you mentioned. It's weird it almost acts like it is running with the choke on all the time. I'm tearing it apart now so I hope to have an answer soon. Nothing leaks and I keep the valve open all the time - this quad is my workhorse and usually is attached to a cart that I use to move firewood and other stuff so it sits outside 24/7. Thanks for all the great tips! Let me know if you know how to detatch the choke cable from the carb? Last time I disassembled this I remember having an issue getting the choke off as it seemed to be held in place by something inside the carb.
Todd Staples yeah, never messed with my carb unfortunately, never had to luckily. I have torn into my Yamaha and the kids Tao Tao quads, this linkage attachments can be a little tricky. Maybe you’re choke cable got preloaded when everything got reassembled keeping your choke on all the time. If your choke is sane as mine, it’s tough to say if it’s attached right or not.
Will the 325 trail boss run right if I bypass the fuel pump and run a line of gas directly to the carb? Also do you have any videos on that vacuum box that's mounted on the head? Not sure what that box actually does. Thanks and keep up the good work.
Jason Day I remember that the quad ran ok with direct feed gas, but I put a new fuel pump in regardless and it runs a little better. I don’t see how bypassing the fuel pump would cause any issues and may increase reliability though my quad idled better with the new fuel pump. As for the vacuum box you inquired of, I believe that is the crankcase breather. Not much to really say about it other than that line connects back in with the air filter box on the fwd side when you reinstall everything to put the quad back on the trail. Hope this helps. Best of luck to ya, thanks for the comment. 👍
Dustin Elgan thanks for the reply
How to set top dead center?
My shifter falls or of gear when I hit bumps. I'm looking to replace that. Is there a website I would I be able to find parts?
Im having issues with my 01 325 trail boss. It will start with the pull start and run like junk. Will not excellerate at all. No funny noises from the engine so i assume its a fuel issue. I cleaned the carb. Changed the plug and end. Drained lines and added fresh fuel. Changed nothing. Please help.
Bob Disandro follow my tutorial for fuel pump fix. Either bypass the pump or replace it, consider replacing all of your fuel lines, they can collapse internally and restrict fuel flow. Hope this helps you.
sometimes its not necessarily the fuel...if it is an older model quad and driven a lot it could be a worn cam lobe. Polaris engines are notorious for worn cams.
Thanks so much.... Very helpful. !!
Hi dustin,i have the same atv,i took carb off cleaned it really well but there is a flat head screw at bottom next tothe float,it has a spring on it. How many turns does it need to be when putting it back? PLEASE CAN YOU HELP ME?
thank you
1982pantro that’s likely your fuel air mixture screw. Screw it all the way in, then count the rotation out at 1 &1/2 turns. That’s a good starting point for adjusting the carburetor. I’m sure there are videos on CZcams that will give you tips on getting the carb fine tuned, if it runs good like that you shouldn’t have any problems. Thanks for your comment and best of luck to you.
Dustin Elgan,thank you so much for your quick response,you saved me a headache. Greetings from arizona.
Dustin thanks for that and can I'm wondering what the clear hoses go to ?
Allen P Christiansen, I believe that’s a gas tank vent line. Goes up behind front handle bar support under plastic fairing.
Great video. Could you explain to me how to bypass the petcock?
Find the line going to the shorter filter going into your tank, plug the other outlet and run the hose that connects to the center connector on your petcock valve to the short filter outlet on bottom of your tank
Is a diaphragm pump it works off the vacuum of the engine
Miss information
Dustin. 2005 Polaris Sportsman 400 appears to operate a very similar system. There is a small plastic line that leaves the top of the fuel tank (through a nipple on the top) and appears to go up into the instrument panel at the top front of the quad. What is that line and what if it is cracked or broken? Also how difficult to replace? Thanks
Ted Wheat that’s your tank vent line, in order for fuel to flow you need to displace fuel with air in your tank as you use the fuel or it will not flow freely. Not a terrible job to replace, just remove the fairings/plastics around the tank and you should have access to replace the line. Worse case scenario you may have to remove the tank to get access to the line. Just replace it with fuel resistant hose from Autoparts store or small engine repair shop. Best of luck to you, thanks for your comment, hope this helps.
I have the same one
I did a full carb rebuild, fuel pump was changed, ran the fuel lines to the proper places and changed the plug. it starts up fine and will idle but the moment i hit the throttle when the quad is in gear it dies out. i tried adjusting the throttle cable but it still does the same thing. my only other thought would be that i used a lower octane fuel to see if it would even run after all the work. could this be a factor or should i look into something else??
Brian Cushler did you adjust the float in the carb? Sounds like you don’t have enough reserve fuel for when you demand more. That’s a possibility, but I’ve never messed with that particular carb. There should be a air/fuel mixture screw that would help you too, you could be running her lean. Did you clean the fuel strainers that connect to the lower nipples that provide fuel from the tank? I don’t feel that lower octane fuel is the cause unless you’re running absolutely old garbage gas, which in that case you’d idle rough if at all. Let me know if this helps.
I'm in the process of chasing down a fuel issue of my own on my Sportsman 700. I replaced the carb and still have issues. So tomorrow I am removing everything and replacing the petcock, pump and all the lines. I was going to try to clean the tank as well. But I'm curious as to how the nipples on the tank come out and go back in? I'm a little nervous about breaking a seal and having a future leak. So my question is, how do they come out and have you had any issues with them after removing them? Thanks!
Mike Boley they thread into the plastic and they seal up fine, nothing to worry about, don't over tighten them. Brass will always win over plastic when torque is in play. Just make sure you take note on which nipple fitting is reserve and which one is the on position so you correctly connect the lines to your petcock valve, my only recommendation for you if you're going for a full fuel system rebuild. I hope my video is of help to you and thanks for your comment. Best of luck with your sportsman 700
Dustin Elgan thank you so much! Where did you get your fuel lines? I was going to try to go to the parts store but someone said the last time they went there they said they weren't allowed to sell him the lines by the foot. They ended up just cutting him a section and gave it to him. Not sure what that was about, but I may have to go online to buy them. Thanks again!
Mike Boley got my lines at advance auto. If any of the big store brands say no, you can't go wrong going to a Napa or other smaller name Autoparts stores. They'll accommodate you better for sure. There's always eBay and amazon as well, you'll need like 7' of 1/4" fuel line I believe, all that info is in the video. Online will probably be cheaper TBH. Best of luck, let me know how you make out.
Also i believe the start switch is bad. The e start wont work. Lights dont work. Nothing electrical works except for that it starts and runs rough
Bob Disandro see my tutorial on headlight starter switch replacement on my channel. This may help you. If that doesn't work check your stater solenoid just forward of your battery. If nothing after that replace your starter and make sure there's no corrosion on battery cable terminals or faulty cables. Hope this helps you.
Hi do you still have this four wheeler and would you be able to help me with finding the wiring I need to get this running? I bought one that needed a cdi box and I have that now but I can not find where the other wires go
Sorry, quad is long gone. Wish I could help
please help me....my trail boss 330 loss fuel for the fuel shut off petcock.....but only one line come to the gas tank at the petcock.....the other 2 holes of the petcock are empties ....its correct??? only one line of the gas tank comes at the petcock?? thanks
madsen madsen there should be 2 fuel lines coming from your tank unless someone changed your setup. So, two lines come from tank to either side of the petcock valve, one line goes from petcock to your fuel pump or to your carburetor if you choose to bypass the fuel pump. If you lost fuel to your carb, I'd start by checking the routing of your fuel lines and also check to see if your fuel lines are compromised/old/collapsed in on themselves affecting fuel flow. Next, pull a fuel line from the tank to see if fuel flows freely by gravity from tank, check to see tank vent isn't clogged, check this by opening fuel cap, if fuel flows better then you'll know it's a venting issue. Next check for clogged screens at fuel nipples in tank, check for clog at petcock valve and fuel pump, then if this doesn't fix the issue check your carburetor bowl and float for a stuck needle and seat. I hope this helps. Let me know how you make out.
Does the express have a fuel pump I'm having issue where its blowing gas back out of carb and gasping at full throttle sum1 help plz
Sounds like your float is stuck, gas shouldn’t be burping out of your carb. Take carb off, disassemble it and check your needle and float. Your float is either damaged and doesn’t float anymore or your needle and seat is compromised or dirty.
Thanks but I finally figured it out ... the skirt on the intake side of piston broke off lol. Last thing I ever would of thought. Good news I'm a certified polaris technician bc I went through every fucken thing on it lol
Technically, the "P" line is not pressure. Engine VACUUM from the intake side of the carburetor "pulls" and opens the fuel-pump valve.
Alvin Ambers thanks for your input, I hope the video was helpful to you. Don’t forget to thumb up 😉👍
Technically, the "P" line IS pressure. Negative pressure, which is also called VACUUM. Negative pressure, also known as a vacuum, is a process that reduces the air pressure inside a container to a level that is lower than the outside atmospheric pressure. @@dustinelgan6070
what is it when the quad acts like it gets to much gas? mine has all New fuel lines but didn't fix the issue?
Sam Remy check your carburetor, sounds like your needle and seat isn't closing all the way in the float bowl. Hope this helps. Let me know how you make out.
check your choke...could be sticking
I have a 400 sportsman 2002 put a new cam in got everything rite now it will run but like crap sometimes it will take off good then it will go like crap then it will idle high then die then start it up and all the same again I need help
Randy Kuball sounds like an electrical issue, check all your connections being that it was all taken apart for the rebuild. It obviously isn’t a mechanical issue or there would be other symptoms. I doubt it to be a fuel issue unless your carburetor was messed with or has clogged insides. I’m leaning towards electrical though. Start simple and troubleshoot from there. Hope this helps you.
Hi i have a Polaris Trail boss 325 and when i start it up and go to put it Forward or Reveres it makes a Grinding sound and shuts off!! I tried pressing the Gas and then putting it in Forward and it works!! But when i hit the brakes it shuts off! Anyone know what to do? We think the clutch is stuck!!Plz help!!!
Colton Bocock start by removing the clutch cover and see what’s going on. With machine off that belt should be loose enough to move with your hand. If the belt is tight and the primary clutch is full diameter, then you have a seized primary clutch. They can be rebuilt but you should also look at your clutch covers and see if you are getting water and debris in there. They are supposed to be relatively water tight to keep stuff from binding and wearing out your clutches and belt.
Dustin Elgan Thanks
The little filters inside the tank where would I be able to feet one
cody h start with a Polaris parts dealer and go from there, I’m pretty sure there’s some aftermarket stuff out there, but I haven’t looked. If you find something please share it so we can help others as they fix their machines.
Amazon
Just send the fuel from the tank to the carb. by pass that fake fuel pump you don’t need it. Leave everything else alone.
I prefer to disable the fuel pump and go directly to the carb from the tank.. the fuel pump operates by pulsation created by rpm from motor. the fuel pump only pumps fuel at high rpm. it will not pump at idle thus using up the fuel that is left in the bowl. watch your fuel filter at idle and you will see it empty out...rev the motor and the filter will fill back. This draw back of fuel can cause a rough idle and rpm take off. I consider these pumps useless seeing as how gravity feed serves best with a constant flow.......(my opinion and i'm sticking to it)
limbslapper one yeah, I see what you mean, makes sense that the pump works when you rev it because of the vacuum line running to the pump. I ran my quad bypassed and connected to the pump, I found mine ran a little better and had a small noticeable amount more power with the pump connected. There’s lots of variables between everyones machines, I was hoping that it would run better bypassed TBH, but mine preferred it. Thanks for your comment, I love the feedback that I get on these topics.
pictures in this link....thanks
madsen madsen I checked out your forum and that trailboss was really poorly maintained, you inherited a basket case. Don't worry, my trailboss wasn't much better when I bought it, just see my channel and you'll see some of the fixes that I documented. My fuel tank had mulch and dirt in it lol. I suggest you fix that pull start sooner than later, the pull start handle acts as a cap to keep water and dirt from entering into that case. I have to fix my pull start as well because the retract stopped working. Your petcock valve is definitely broken and not connected properly. The two lines you mentioned coming from the carburetor to the fuel pump in your forum is correct, one line going to the CVT belt side/petcock/LH side of your quad to your carburetor is your fuel feed, the line opposite/exhaust pipe/RH side of carburetor is a pressure/vacuum line that makes your fuel pump function. Whoever had your quad before bypassed the petcock valve which is ok, I wouldn't worry about it now, it's functional that way. The single line going to your petcock valve may be coming from your reserve or fuel on nipple from your tank because it has nowhere else to go if I had to guess. If you're not getting fuel to the carb, run a fuel line directly from your tank to the fuel inlet on your carb to troubleshoot if your fuel pump is working or not. Don't worry about disconnecting the vacuum line to test this. If your quad runs with this setup then know you have a faulty fuel pump. I did another video on how to do this bypass, check my channel. Hope this helps you out.
madsen madsen the line going to the petcock, take it off and plug it. It's doing nothing for you, just leaking all over the place. That valve is to allow you to run your quad with the option of having a reserve when you run low on fuel when put in the on position. Right now that valve is bypassed and that valve has one of the two fuel lines ran to the valve acting as a plug that could be opened, really a bad unsafe way of plugging the line.
Come work on mine
The fuel system as it is set up with this quad takes a little bit to run the air out of the 4-5' of hose from where the gas enters to where it finally gets to the carb. I'm going to ask you some questions and hopefully I can help troubleshoot the issue with you. It's a frustrating system, I'll add in a few tips that helped me. Feel free to email me your number if none of this works and I'll gladly call you and talk with you if you'd like, versia23@hotmail.com. Do you have a clear fuel filter like I have going to the fuel pump to see flow? Did you check your nipple fittings coming from your tank to see if mesh screens are not clogged? Is your tank properly vented to allow fuel to flow in that system? I blew into the tank once to push the fuel through the system, you can try that. Does the pressure line allow the pump to work, vacuum leak issues with carburetor anywhere? Is your needle and seat for your carb potentially sticking in float bowl? Try disconnecting fuel feed line going into carb, hold line in container, run the quad on starting fluid and see if fuel primes your line that way. If it does fuel will flow of nothing else is compromising your system. Check that all your lines are hooked up right. If that doesn't work, bypass the fuel pump as described in my other video and see if the quad will run. If it still doesn't run, and you can't get fuel from your tank to the carb, then take your tank off and investigate. Clean out your tank, put in fresh 93 octane fuel. Check for pinched fuel lines, replace all fuel lines of not already done so, push compressed air through lines (not through new fuel pump). Fuel should readily flow by gravity from tank without assistance. Once fuel flow, fuel lines and petcock are out of the possibility of being compromised, it's time to look at the carburetor float system and vacuum system to see if they are compromised. Let me know if any of this helps.
alright Dustin thanks. hopefully with your help I can figure this out.
Hey dustin I took the fuel line that feeds into the carb used starting fluid and tried a few times. first off a reddish colored liquid came out then it cleared up but it still won't run. if I pull the choke I can keep it going for a little bit but it still won't run. I'll e-mail you my number and maybe we can solve this. do I need to pull the carb off.? I replaced all the fuel lines and pump so I don't know where that nasty red liquid came from since that was before the carb. well any thoughts.?