Briggs & Stratton plastic carb priming issue easy fix
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- čas přidán 5. 09. 2024
- If you have a plastic Briggs & Stratton carburetor that will not start due to primer issues, then check out this quick easy and cheap fix. My lawnmower wouldn't start without starting fluid but now it starts on the first pull. All the primer did was push air and not circulate gas in the carb before. If this fixed your problem, comment below. I just want to help others with the same problem. This is my first video please go easy on me in the comments, I'm 19 years old and enrolling in automotive technology at college and I fix up small engines as a side hussle and as a hobby, I've learned a lot from it. Thanks for watching
Spot on! Thanks so much for the tip! You just saved me a whole lot of frustration! I have a E500 engine on my mower that worked for about a year. All of a sudden this past month, priming no longer works. Followed your advice and BINGO! Works like a charm again. Interestingly, in my situation, the primer bulb WOULD pump gasoline into the carburetor throat--in fact it would eventually run out, down into the air filter and drip onto the deck! I'd spray a little ether in the carb and the engine would start with (literally) a BANG due to all the liquid gas sitting in the throttle body. So my theory is that the primer bulb was still putting enough pressure in carb bowl to push fuel up the emulsion tube into the carb body, but not with enough force to atomize the fuel--it just sort of ran in as a less ignitable liquid instead of a fuel/air mixture. By blocking that white nipple as you suggest, the force of the prime is now sufficient to areosolize the gas so it can be sucked into the intake manifold properly.
Again, thanks! Sure beats those so-called "prefessionals" elsewhere on CZcams that entoned that the problem could only be fixed by replacing the carb!
Q!
Mark, you are on the right track! The purpose of the little white plastic fitting is to aloe air back into the red priming bulb for those folks who hold their ginger over the hole in the red primer bulb and DONOT lift it between pushes! Only problem is this white plastic vent makes the red primer bulb less effective priming! I had prime mine like 10 times to get to start because my carb has NO CHOKE! I put a bit of chainsaw tubing on the white fitting like you did, and it starts with 3 or 4 pushes of the primer provided I lift my finger off the center hole in the red bulb between pushes! Starts with a couple pulls, and since this fix doesn’t effect the carburetor function the fix works great!!
Definitely glad for the explanation, it makes a lot of sense. I wasn't sure why it worked myself, but that it just worked, thanks!
i just serviced 3 lawn mowers today and this mysterious grey object fell out and your video set me straight TY
It works! Started on the 3rd pull. This is a brand new lawn mower that I bought 2 months ago and would take too many pulls to count before it would start.
I'm glad it worked for you
Good job. Thanks for the video. I lost the white piece. I was thinking to just cover that hole. You saved me a trip to the parts store.
Great!
My husband has worked all day - literally, except for lunch - on this very problem. Finally took carburetor off and cleaned it thinking it had to be the problem. Still wasn't getting gas - no noise when you push that red primer. I can't wait to show this to him - hope it works - tomorrow. He finally quit. Not even our mower - fixing for a neighbor.
Let me know if that fixes it thanks!
Thank you! I watched 100 videos but yours was the one that fixed my problem. Just putting my finger over the white part when priming did the job.
Glad it was helpful!
I watched a dozen + videos,,I cleaned this carb a few times and nothing changed, however yours fixed my problem, I plugged the hole with a tiny cotter pin and its working like a champ, starts right up no problem,, whoever thought of the vent hole needs to own that style mower to see how it really works, I was about ready to throw it in the trash, good job, thanks Mark, you should send to manufacturer
Thanks🎉 Basic and to the point explanation.
I used a vacuum cap, it works great now thanks for this video!
Got a craftsman mower here with that exact problem. I'm going to clean up the carburetor and take a look at what this video has illustrated. I'll try to get back to ya on this.
Great, let me know if it works for you too
Thank you! Just about to install a new carb on the lawnmower mower
At the last L&G shop I worked at, I had 2 five gallon buckets full of these carbs. After a while, they start dissolving . Ergo, new carb.
Thank you so much for this video it helped a lot on my mowers caurbourator.
Great discovery it worked all I have to say excellent
My brand new ( July 2021 ) Troy-Bilt mower is not priming. Starts and runs great after 7-10 pulls but should start after one pull if it primes correctly. Exact same carb setup. I'm going to try this - thanks!
Thanks, great fix, you should send to manufacturer
I just bought this same mower. Right out of the box it will not prime. I’m so disappointed in Brigg’s quality now.
This fix worked for me.
It seems like that fitting should go somewhere. I spent 2 hours looking for another fitting to connect it to before I found this video.
I have looking for a fix for 3 years tried new carb same thing hard to start .l blocked that vent works now thank you !!🙌🍻
Thank you thank you thank you thank you… My shoulder. Thanks you as well.
😊❤😊
Hi thanks a lot for your helpful video. I have recently exchanged the carburator because the engine didn t start up any more. For 3 times it worked, now when I push the red bulb there actually comes gas out the little white nipple that you closed on yours. Do you think just closing it with a tube should do it or is this a sign of another problem ? Thanks very much for your comment....
@@docholiday4338 i would at least try it to see if it helps. If it doesn't help, spray a small amount of starting fluid or similar into the carburetor to verify it is a fuel delivery issue. If it kicks off with staring fluid, I would suspect the carb is already dirty or bad. Check your fuel line to make sure it isn't deteriorated causing a clog in the line or carb. I have also had these carbs go bad shortly after install or even put of the box.
Very helpful, thanks.
You are very welcome
Thanks 👍😊
Hi great tip and yes I have this same issue from day one of my all new mower, so I will try this out but have you contacted Briggs and asked them what is the white barb like tube on the right side if tte carb for.
I think that you are on to something as the auto choke carb version of this engine does not have the white barb thing.
Same thing I did.Engineers make big bucks to design stupid shit.
the problem is not that white part that makes it to not prime the real reason is the red rubber gasket the carb has in time it gets thinner and thinner making it hard for the carburetor and the filter housing have a tight seal sometimes the filter housing gets warped also like in the other briggs push mowers so change the red gasket for your not priming issue
That makes sense @CHARRITO LOPEZ, but I do know that this trick does work, I've fixed 4 like this so far and has fixed all of them. sounds like there was some planned obsolescence.
There is no hole on the plastic piece on mine. Its been run about 5 times and has the same issue. Still working on it.
F ME !! Unbelievable lol - you’re awesome bro. Thank you.
I’ve tried that but still not getting a prime
Same here. Did you ever figure out why? Thanks in advance.
I have the same problem, I have put 2 new carbs on and still it does not prime. any help would be appreciated. Thanks in advance, Charlie from Muscle Shoals Al.
What about the issue with the passage that gets blocked or the whole double gasket?
Hi. Thanks for this. I have been trying to fix my son's 450e for a couple of weeks now. You're the only youtuber I have seen who have identified this issue. Having stripped the carb, and followed the instructions, it still won't start. I have an ignition coil on order, as I'm not sure that I am getting a spark. It's a 2017 manufacture. Do you know the clearance for setting this coil please. Someone had been messing with it before he obtained it and the coil was in contact with the flywheel. One youtuber says 12 thou. which I have tried (I have fitted a new plug) . I have found items saying that gaps can go from about three thou to fifteen thou, consult the manual. The online manual is quite hard to read, I can't find any specific spec. for the 450e. Thanks in anticipation.
Im not sure off the top of my head what ignition coil air gap should be on that mower, but if you set it between 9-12 thousands, you should get a strong spark. If not, suspect your coil, spark plug, or if there is no spark at all, check to see if it has a ground terminal on the coil as some safety components use the coil to ground thus preventing spark.
Thank you.
@@MStanleyRoss use a standard paper business card ,place between coil and magnets on flywheel, loosen coil screws till magnets draws coil in to paper card, tighten coil ,slide card out and you ARE SET, to test coil place a ohm meter on 20k ohms from spark side of coil wire and coil metal body ,see that it shows ohm reading of .5 ohms or more your coil is good, no reading' coil bad. ,[also test black kill[ground ] wire to engine frame should read 0 ohms] , hope this helps
@@mickeybaker7877 cheers m8. Went to screwfix and invested a few quid in a set of gauges. Got it set up at 10thou and did a bit of the neighbours lawn. Tweaked it to 12 and it was humming like a good un. I am a silly old fart but I do get a kick from problem solving and saving stuff from the skip. My lad has cut his lawn a few times now, we have not been short of rain. He loves his old dad. I painted and papered his spare room last week!
Thought I'd found the answer to our prob for a minute, ours only runs after starting and pressing the primer for a while then it'll run it hunts like mad, but covering the little white nipple then pressing primer makes it nearly stall. Our mower has only done about 3hrs since new but to old to take back. any ideas. I have stripped and cleaned the carb but it's clean as it's so new.
Thanks for the vid anyway.
As much as it may be hard to believe, the carb may still be dirty, there is a white plastic cartridge with a couple brass jets fitted inside them. Those jets are the smallest I've ever seen and they often get clogged. Try that first, then check your linkage from the governor to the carb. If that doesn't fix it, check for any blockages in the air filter and airways and make sure nothing is obstructing the exhaust. If that doesn't fix it, it may be time to replace the carb. They didn't make those plastic carburetors to last and you can pick them up on eBay for about 15 Dollars. I have done this and they work just fine. Let me know your results
Unfortunately it didn't work for me. I even tried a rubber plug from car and still it didn't work. Have to pump the primer bulb about 10 timesto start.
hey buddy I noticed the same thing with the whole..I replaced the carb and the new one leaks gas from the primer bulb and the white nipple. I'm not sure if it's the same problem
Odd a new one would leak but I've seen bad new carburetors out of the box. Try this trick before replacing it again it may or may not help in your situation
Did you cover the hole with a little plastic?
It was with some chainsaw/weed eater fuel line I pinched the one end of the fuel line together after heating it up. I essentially just prevented that nipple from leaking air.
My primer floods the spark plug with fuel with once push of the bulb. Won't start til I wipe off the plug. Took apart the carb and cleaned everything but it still squirts too much fuel into the cylinder. Fuel even comes out of the air cleaner and drips onto the mower base. can't figure this one out.
Sounds like a needle and seat issue in the carburetor. Probably best to buy a new one from eBay for 15 bucks
@@markbierly2469 I cleaned the needle and seat a couple of times. Installed the carb and tank with fuel. Left it sit over night but no sign of the needle not shutting off the supply to the bowl. Plug and the area under the carb remained dry until I pressed the primer bulb once then the plug is soaked with fuel and fuel came out to the filter. I take out the plug, dry it off reinstall it and the mower will start on the first pull and run just fine til I have to prime again to start. Not sure how this primer system works.
@@trainmaster0217 I see what you are saying now. I'm not sure of any way to prime less fuel other than priming it less. Other than that, it might be worth a shot to install a new air box housing with new primer bulb.
@@markbierly2469 Thank you very much for your replies. I think I will take your advice and give it a whirl. One new airbox with primer bulb coming up.
@@trainmaster0217 not positive it will correct the issue but shouldn't cost more then $20 to try on ebay/amazon worth a shot at least. If that doesn't work, a new carburetor may be the cause
Why do I have to prime the engine? Every time I've turned it off?
When you "prime" your engine, you are introducing a gas vapor mix into the intake to allow the engine to start easier. Engines use more fuel to initially start. If the engine is hot and you restart it, you shouldn't need to prime your engine. If you do, you may have a dirty carburetor.
@@markbierly2469 Thank you
I couldn't catch the info about the little yellow plastic line that fast missed it could you explain?
It's just weedwhacker/chainsaw fuel line, it's the yellow stuff but I can't think of the name of it. It's smaller than 1/4" I believe it's 1/8" but Im not 100% sure, pull the carb, or just pull the plastic insert out to size it up and use what fits. Just cut yourself anout 3 inches of it, heat the one end up with a torch, and pinch it shut with pliers. You can trim the other end off to make it shorter so it doesn't stick far off the carb
Mark has it right, I would add use maybe an inch and half of even two to melt the end, so when you are putting it on you aren’t fighting the air trapped inside , I used like an inch and had a hard time getting it on the fitting!
Those white fittings are supposed to plugged on the inside. Pull it off first to make sure you are not doing something for nothing., lol
When I start priming mine it starts leaking through the filter part do u know what it could be ?
Possibly a stuck open or bad needle or seat in the carburetor. It could also be a broken or leaking float in the carb as these are non-adjustable floats.
@@markbierly2469 Thanks man
@@garrycoleman2494 some leaking is normal, you'll see stains on the filter, that's normal.
So everyone……this primer type set up doesn’t not have a tubing connection to the plastic carb at all ….I’d like to hear from the designers of this and ask them the logic “why” It’s a pain to say the least …..I’ll try sealing the white barb……
Let me know if it works for you
These mowers have been a royal pain in the derrière …..I never had issues with the mowers we had growing up ..NEVER…..Every time I use this Sears Briggs/Stratton I have to mess with it …I still want to put a small inline fuel filter on it to reduce the fine particles that block those jets in the center white plastic assembly……
I haven't had mine off, but thinking about it, it seems to me that the only way this was supposed to work is as a check valve. A little BB in there that closes when you push the primer and then pulls back with suction to allow more air in for the next pump. I'm theorizing that little BB gets gummed up and doesn't do it's job anymore? Just a theory, but at least it hits all the symptoms. Like somebody above said, the need for this thing can only be to avoid the need for the user to lift his/her finger off the primer bulb between pushes, which allows in plenty of air through the little hold in the bulb. When the BB fails, it reduces the pressure in the priming system enough that gasoline still is pumped into the carb throttle body but not as an aerosol, which then acts like a flooded carb and the engine won't start as a result.
Anyway, Mark's fix works, whatever the cause/theory!
Q!
Does the mower keep running?
Yes it does
As Mark said the little fitting only effects priming and isn’t doing anything after the mower starts!
It didn't work. He tried everything. He went to the shop where he has always done business (he is the mower whisperer!) and they said those plastic carburetors are junk - they don't even try to fix them. But he came home, took it off again and took it all apart and did it all again. Didn't work. :-)
Unfortunately I've run into the same issue. one of the plastic carbs I took apart had a press fit brass jet just laying in the bottom of the bowl. They don't hold up well over time so I definitely agree with the shop, but its always worth a shot. Good thing they don't cost much on eBay or Amazon!
What a piece of junk! If you bought one of theese, take it back.
I'm having this same issue and it would have done the same thing if you just put your finger over the hole while you prime it. The gas will come from the bottom shoot instead of the primer tip. Ether way mine still isn't starting
Did you ever get it to work