The Complete Guide To The Mikuni VM22 On Predator and GX200 Clones
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- čas přidán 25. 06. 2024
- The comprehensive guide you need to successfully select, setup, install, tune and adjust the popular "Mikuni" VM22 Round Slide Carburetor on your Predator 212 and GX200 Clone motors. Covers everything from why you should switch to the Mikuni, the various fuel circuits and their operation, selecting the proper jets and dialing in the tune for your particular motor.
Chapters:
0:00 - Why a VM22?
7:07 - How Does It Work?
19:35 - The Needle Jet
26:29 - Adjusting The Carb
31:50 - What Jets Do I Need?
35:55 - Which Kit To Buy?
This video is one of if not thee best video explaining which carb is best with the predator 212 ! Ty ! I’ve saved this to my building predators . Mandatory for all mini bike builders .
This is exactly what I needed! My need biuld was bogging out now i just hit 57mph on it! Thank you so much! I put a 130 jet in and ordered a 127.5! Im actually learning thx to you how to work and tune my own bike!
what a good video!! i like these so called “cheap carbs “. other videos make it like “cheap” is bad. i think “cheap” is less expensive. others think “cheap” is junk. these r good inexpensive carbs. i appreciate this guy exsplaining how they work. THANK YOU
"less expensive" is great as long you find the ones that weren't cast in some guys apartment out of old beer cans lol.
This is a great video. Thank you for the information. You helped it all make sense.
I appreciate all of the info but especially the specs you run, most people never tell. Thanks
Awesome video, very informative. Thanks
Awesome video! Very informative, thanks!
This is the best informative video I found out of all
thanks! awesome knowledge your giving away!
Excellent and thorough explanation of the carb in simple and easy to understand language. Very well done and thank u
Very very detailed. Loved every minute of the video. Thanks a ton!
Thanks Alaric! I hope it was helpful. We appreciate you watching!! Subscribe, there’s a bunch of good stuff coming thats being edited now.
Thumbs up two thumbs up
Brought a mikuni car today it barks down on full speed guess I need a bigger jet
I tried your table top method to remove and install the e-clip and it works! I mentioned you in the video and put a link to your channel in the description. I didn't try your tip out until later when I switched to a wood work table but man it worked great! Thanks!
Wow this was so informational and easy to understand. Thank you. Great work here and awesome tips.
Thanks Im new to this and have a ultra rich PZ30 on a 212 Predator (Gov. Removed) Mini Chopper. I started it on a small stand. It was like a beast trying to break free from a circus. Your video will be the one I refer to in the days to come. Thank you and keep making quality videos.
Great video John. Top to bottom, this video will explain everything. Well done.
Thanks, this is a great video, best I've seen on tuning these little carbs.
Thank you!!!
how can anyone give thumbs down on this video.. well done sir. I have one on the way and now I feel soo much better about working on it.. thank you.
This guy is great! Very engaging and super informative about the various knowings of how shit works. Keep up the great work!
I have shared this on so many mini bike facebook groups.
Thanks for this video helped my buddy and I out a lot
Great info, thanks much!
Great informative video. This is exactly what I was working on today. If I'm at idle and I crank the throttle it bogs down or wants to die. If I ease into it, it's just fine. I just put a 140 main in, and am getting a 17.5 pilot. I was having the issue you spoke of with the air fuel screw not changing the idle. Hopefully I can get everything to sync together.
Thank you. Awesome video!!!!!
Seeing this two sparkplugs too late but at least I won't start the engine any time before I got the bigger jets... Thanks for the video my man !
This video should have a lot more views
Got this carb coming next week for a 2 stage Tillotson 212, this video is an excellent tool for me, thank you!
How fast your going?
great video very helpful i also saw where you offered help to someone at your shop no charge, you Sir have earned another subscriber 👍
Great video. Thank you.
Great info. thanks for the link too.
I know it's old but still extremely helpful. Great emulsion tube explanation and the effect of the clip position. Oh and thanks for the clip removal nugget. The problem I'm having is with another slide carb, FCR, for my Honda CRF250X and plan on checking the clip position tomorrow! Subscribed!
Good stuff, very helpful.
I've found the needle to be very useful for tuning part throttle between 1/4 and 3/4. Especially if you're having trouble with quick throttle response hesitation. Helps get the fuel flowing from the main jet faster.
Thank you so much. I thought i knew some about the Mikuni knock-off, but you really opened my eyes to the nuances of this carb. If you could verify my thinking I'd appreciate it. I live in Colorado at over 6k ft, but often ride between 9k-12K ft above sea level. Therefore, am running a 120 main and 12.5 pilot with the needle at the next to the last (top) slot. Historically with the stock jets it was pretty rich and my plug turned black with soot.
Great explanation! New subscriber here! Looking forward to seeing more!
awesome video
Thanks for the lesson
Great job on the video! Mikuni has 3 types of main jets. Large Round (the one in the video), Small Round, and Hexagonal. Hex are usually found in 2 stroke applications and start at 130 or 150 I believe. The large and small round have different thread pitch so you do have to figure out which you need. To make matters more difficult, Keihin also uses similar looking jets and they are not interchangeable with Mikuni stuff.
And then to complicate things further, some keihin clones look like keihin jets but fit mikuni clones lol
I melted in my seat enjoying this man information is all spot on . Thank you! I have a few videos of my 110cc upgraded to a 125cc.big bore kit. We need to become best friends tha k you again!
Ok, BFFs it is!
Gunna greatly jet down today! I believe I'm running richer than Bill Gates at auction. It falls on its face wot. I'm figuring hopefully jump down to a 85 on the main and 15 on pilot.
I don’t have a lot of experience jetting these for 125’s, but I would start somewhere in that neighborhood too. Just read the plug and adjust from there, and remember, a little rich is better than lean.
Thank you very much!!!
Now I know that my main jet is just too small.
My Lifan GX 160 engine is hard to start, even with the choke on. When I screw in the idle speed screw, the engine starts up nicely, but has a very high idle speed, and loosening the mixture composition screw increases it even more. Of course I can lower them back by unscrewing the idle screw, but the engine will be hard to start again. I have the original Japanese Mikuni carburetor fitted.
I will order a larger nozzle and it will run like a dream. Of course, I dismantled the regulator, but NOTE: here is a small curiosity - after removing the regulator, there is a hole on its axis, at the top of the engine. This hole acts as a crankcase breather and some oil "mist" is emitted from it.
You can screw a rubber hose in this place and install it in the valve cover - then we have additional lubrication of valves and levers;)
Sorry for my bad English.
Greetings from Poland.
Dam I just ordered the thing wow salty thanks for letting me know ...
Governors are set to 3600. The stop screw on the throttle linkage may stop the engine from revving beyond 2500-2800...but with the throttle linkage set to wot, the governor will limit revs to 3600. I often put a bend in the spring going from the throttle linkage to the carb, effectively shortening it so that the engine will rev to 4k-4200. Above that speed, it's best to remove the governor. 3600 rpms is the standard speed for outdoor power equipment. Also, nice to see the bowl gasket tip...I ruined several gaskets before I realized that you can't get fuel on them. Sometimes, a bit of heat will dry them out enough for them to go close to the original size.
You can run much higher than that with the governor and stock linkage. I do.
great video thank you, i just put that carb on my bike got it running perfect took it down the road the magnet flew off the flywheel and broke the coil off the block, off to harbor frieght we go
Those honda clones 212 predator motors and the like are designed to run 3600RPM. I have the stock carb and its plenty good for 5K with stage one air and header installed. No need to spend money on a carb unless you plan on going over 5k RPM
this is hopefully my saving grace video lolol, i just installed a VM22 on my predator 224, i got it to idle pretty good, but spits, sputters, and dies on Acceleration...i did not even open the carb up and getting the info most are underjetted is a huge relief!!!! it def feels like im not getting enough fule on acceleration
Thank you very much this has helped me out so much....however my needle has a weird plastic cap on it that idk how to remove with a small spring so idk how to adjust my e clip
This guy knows what makes it Chooch
You have no idea how bad I needed this video. I am officially subscriber #501!
Awesome, welcome to the family! Thanks for the kind feedback. If you get hung up on dialing it in, drop us a message on Facebook (it’s checked more often). Cheers-
Great video! I just put this on my new to me coolster 125. I put on the foam filter in came with. What should I do with the breather tube that was also plugged into the air filter on the stock setup ?
mine had a 130 in it already...the guys at Go Power Sports must tune these things before they send them out...might still have to tune it some more though, since I'm sticking it on a 228
Love this vid, the best explanation of the VM22 on here, on mine, (it's genuine) I'm told the carb has the right jets for my bike, but the plug getstotally soot black (not oily wet), but the tick over is beautiful, nice and even, but just starts running rough when opening up, runs nice, but after a few miles it gets too bad to run, put a clean plug in and it's fine again, I suspect a smaller main jet is needed, question: how many sizes down do I go? or do I drop the needle a notch or two? sorry for the dumb question, just learning about this carb, thanks for your time, Dave have subscribed!
So, the needle position starts affecting things around 1/4 throttle to a bit over 2/3 throttle. After that it has only a minor effect as it has lifted almost out of the needle jet (the part it slides in and out of. The bottom of same, holds the Main jet). Wide open throttle is main only. The bike will run great without the main jet installed in the carb until you get to about 3/4 throttle. Then it would run real rich afterwards unless your needle jet is too small (rare occurrence).
I’d try leaning it out on the needle; if you get to the top notch, switch down (leaner) 1 jet size and set the needle back to full rich (bottom notch) and continue leaning it out from there. Sooty can also be caused by too large of a primary jet (just adding too much fuel all the time) but it’s unlikely unless you’ve increased that primary jet size before. Hope that helps, sorry for the slow answer.
@@bahnzai7313 thanks for the reply, the bike has been running fine for miles, I ended up screwing the pilot screwing in, it's now a quarter turn out. I know it's not how it should be, but bike runs fine now. The plug colour is dark brown, could be a bit better, but I'm happy with it, certainly don't want a lean running bike. Anyway, thanks again.
grate you helped me heeps
I suded
Think you for posting this video it has been very helpful to me not very familiar with the mikuni knock off. Would you please give me the website that you mentioned there in Florida? I'm running extremely rich at idle with a number 15 p-jet Thanking I'm gonna have to go to a 12 jet Unless you have some of them laying around that I can purchase from you? And almost forgot to mention I am running stock valve size
Just installed one on my rfz and it seems like it’s just flooding the carb, i tried to replicate the air screw based on the stock one where it was on the threads. Just dropped the needle and am gonna try again in the morn. Hope this will solve the problem of the bike not even trying to start
This was an amazing video. First time I actually understood the basics of tuning a Carb ! Thank You for all You help...I am in Jacksonville Fl too....How do I get in touch with You?
Easiest way is message through our Facebook page.
Ok great video. Just had one question. I thought 0-1/4 was idle jet, 1/4 -3/4 needle jet, then 3/4 - full is the main jet. Is that wrong.
Just order from gps hopefully it’s the solution to my bike it start to bogg out on me at full throttle for a bit,my governor is removed stage one with upgraded springs hop this does it 🙏
This is an excellent video. I have a question. Does turning the air screw in (clockwise) lean the motor, and out (counter clockwise) rich the motor?
That is a great question! Similar looking carbs can have different idle circuits. Turning the screw out can increase air or fuel depending on the circuit. Here is how to tell which is which without tearing apart the carb. Look at the relationship between the idle mix screw and the throttle slide. If the mixture screw is between the engine (closer to the piston) it meters fuel. So, out to enrichen, in to lean. If the mixture screw is between the throttle slide and the air horn (air filter), it meters air. So out to lean, in to enrichen. I hope that helps you. Works with any brand slide carb I have ever had on the bench.
@Deucealive75 Thanks for the feedback, and for supporting the channel! Regardless of whether the screw is metering the air or fuel, its purpose is to adjust the air/fuel ratio at idle, hence it typically being called the “Idle Air Mixture Screw”. I’m probably going to do more Slide Carb videos; what terminology do you feel is more accurate? Thx again- Cheers
Will a mikuni carb make my pit bike faster ? I currently run a 26mm kein
I took out my main jet and emulsion tube and a little brass piece fell out. I didnt notice it in my other clone. Does it need to go back in?
I’ve got this on a go cart with a predator motor. Bought it from a friend. Got it started with starter fluid just can’t keep it running. Hoping your showing me where the needle valve goes through the jet and cleaning that out helps. I’m close to Jax I’m in Callahan.
I still can’t get it to stay running. Got it going with starter fluid.
Message us on Facebook, there are a few things to check, but we’re happy to help.
Vm22 26 mm 35 pilot, 115 main, good place to start
Mikuni valvola piatta,the Major ,my favorite in Italy ,the tag dell'orto in the best........in the world .... Grazie the video wonderful!!no speak english 😂😂😂😂 sorry
Hi i m from Argentine .which is the carburator do you say 30 mm with acelerates pum? Excellent video 👌
Thanks Marcelo. The Pumper carb mentioned in the video is still in development, but should be available sometime this year and looks like it will be a game-changer. Subscribe to stay in the loop, and follow us on Facebook for the latest info.
pls, help me! is it okay if my VM22 only gets settled in about 5 rounds? screw head (mixture air/fuel) sticks way out of its little house/hole
Where did you get that perfect mini adjustable wrench? I neeeeeeeed one
Right?!? It’s a little cutie, ain’t it? I have no earthly idea where it came from; likely a combo pack of different sized adjustable wrenches or something, as I don’t think I’d ever buy something so seemingly silly and useless, but it’s awesome for little tasks like this.
Does the carb mm size matter? I bought a 28mm carb and plan on tuning it with the same jets as spoke of or do I need to reduce or go bigger in size ? Can you advise please @bahnzai the motor is a 212 mildly modded
Ultimately yes, carb size does matter, particularly in a single cylinder engine where we have such dramatic reversion of the intake charge when the intake valve closes (and there are no other cylinders wanting to suck in the charge). Because of that phenomenon, I like to size the carburetor just a little bit smaller than the intake valve, to try to get as much velocity as possible before it slams into the reversion wave.
Having said all that, a 28 is a bit bigger than I would have chosen for a mild motor. Sure, if we were talking about a methanol breathing monster with big valves, maybe, but on a less demanding engine you might find some tuning quirks and stumbles that you just have to live with. Or maybe you won’t; just gotta try it and see.
With regard to jetting, I’d start about the same size as I’d start on a smaller carb, like a 20 Pilot and 125-ish main, and tune from there. Maybe a tad richer, knowing that we’ve got a lower vacuum reference drawing fuel up through the jets. But then you might get fat when things start chuffing. Just going to have to play with it. Maybe go bigger on the Pilot and conservative on the Main; that’s what I’d try. Let me know how it goes. Cheers.
I came to figure out which is a good hand throttle to use for vm22 carb. because my stock throttle wouldn’t fit into the carb.
I have a 1961 Harley pan head flh and just replaced the linkard with the round slide Mikuni vl 38mm. Anyone know what jets to use and were to set needle.
I am curious about the Carburetor with an accelerator pump. Have you made any progress on that. I have always wondered about the lack of a pump on these small engines myself. I have always guessed that these engines are designed to run at a constant RPM and so weren't equipped with an accelerator pump. Do you have a website where you would sell such things?
I agree, four stroke engines should have accelerator pumps. The carburetor we’ve been messing with is the Keihin PZ30B, but we’ve been unable to dial enough of the pump shot out to get rid of a rich stumble. If they made a 26-28 variant it would probably work better for small block GX’s, as the 30 seems to struggle to maintain decent charge velocity at lower RPM’s.
Hi, Loved the video. Just received mine for a gx200 clone, installed it but now I am concerned, since it only started once. Has Spark, fuel and air, engine ran good with the stock carb. Sometimes when I try to pull start it, it misfires out of the carb. Do you have a tip how to get her running?
I appreciate it👍
Oh, the main jet is a 125, all I had on hand.
Remote diagnosis is always difficult, but firing out the carb suggests that the intake valve might be a tiny bit open; check the valve lash and make sure it's set to .003 on both sides. Also, a drastically lean mix might fire off too early, so confirm your jetting is right. If you're in the North Florida (Jax) area you're welcome to bring it by the shop and we'll have a look at it for you, no charge.
Thanks, I got it running meanwhile. Turned out the previous owner took the key out of the crank and the flywheel spun about 60 degrees when I tried to start it. Put one in and she fired right up. I couldn't bring it over anyways since I am from Stuttgart, Germany but thanks for the offer😉
@@bahnzai7313 just wanted to say, that right there "you're welcome to bring by the shop an we'll have a look at no charge" that's a sign of a great person right there an very much deserving of a case of beer!... i'm from australia a cartoon(case/box) of beer is how we show our gratitude for help and a job well done.......
Thumis us where im Having issues, i got a predator 224, straight pipe, gov delete, vm22 carb, im at a 140 main and 15 pilot, 5th clip on needle, and still seems lean as far as i can tell.....ive check fir air leaks, sprayed around engine n seals and nothing for leaks....any ideas?
I need a carb and the spec of witch mukuni carb is in my 125ke kawaski
Subscribing so I can find this video again I’ll also check out what else you’ve put out
What altitude are you operating, above sea level
That’s where do you oder your jets from thanks
my chinese mikuni seems to be very rich, stage 2 212 here. Blows blavk smoke at idle and wot and very stout smelling exhaust. What jet would you recommend to get this running right?
did you figure it out? having issues myself with this carb
If you look on some of the distributor's sites they say that the genuine Mikuni jets won't fit on the Chikuni carbs !! They sell the aftermarket jets on the sites for the aftermarket Chikunis !!
True, the standard VM22 jets are no bueno; generally the VM26 jets fit but occasionally you get a weird one. It all depends which factory in China cranked out the one you bought. Niche Cycle has an excellent web site with pics and dimensions of the various jet types, they’re our go-to.
you can boil the bowl gasket in water for a few minutes and it shrinks back up
Hi mate, new to this... i just got the vm22 added the 125 main jett fitted to my mini bike a fuel just flooded through it.. out the bottom tube and even thru air cleaner.. any ideas? Cheers Brad Australia
If the carb is overflowing it means that the float and needle/seat are not functioning correctly. It’s not uncommon for a little bit of debris to get stuck up in there, or sometimes the little rubber cone on the needle (the needle *valve*, not the needle jet) becomes hardened. If it’s a new carb it’s more likely that there’s some junk in there preventing it from sealing.
Pull the bowl off and spray some carb cleaner down through the fuel inlet. Have a look at the float and the tab where the needle attaches to the float, make sure that lifting the float pushes the needle up into the seat. That tab can be bent to adjust the fuel level in the bowl, but if it’s fully overflowing that’s not likely to be the problem.
Button it back up and reconnect the fuel. If it starts overflowing again try tapping on the carb body near the fuel inlet; sometimes it can help the needle valve to seal. If cleaning and tapping doesn’t help, then it’s possible that the float isn’t floating, or the needle/seat are damaged.
Let me know how you fare. Hope this helps.
Thanks for the great video. Truly helpful. I’ve got three stock Hisun 196s and am adding the basic “stage 1” of intake exhaust and 18 lb. Valve springs.. I’ve also installed 60 tooth sprocket on one of the bikes (CT200u-ex) I’d love some advice on the jet sizing for high altitude. I’m at 7,500 before I even hit the trails. Any suggestions? Thanks again!!
Jeez. I was in Leadville Co once, I think it’s like 11,000 feet or something, and I couldn’t breathe. Like *panicky* couldn’t breathe. However, the Turbo Volvo 850R that the car rental agency had thoughtfully provided (right?!?!) didn’t seem to mind at all. So, about all I know about altitude is “jogging bad / turbo good”. Well, that, and you’re going to have to jet down a bunch. Because, you know, no oxygen and all that jazz. If I was racing up there I’d probably want a really oxygenated fuel, like M5 Methanol, but since you mention trails, I’m guessing we’re running good old Dinosaur Juice.
Anyway, there’s my useless advice. Other than boost (hey, how about one of those little AMR300 or 500 super chargers?!!) I’d say just jet down, pack light, and get a run at the steep stuff. I wish I had a better answer, but since it’s 7pm and this is the first time I’ve been irrefutably useless all day, so be it.
Where are you from? Gotta be Colorado, or Utah? Montana? Maybe Idaho?
The clip holding the needle jet down in the slide. Let's call it the "w" clip. Does it matter which way it's clocked inside the slide?
Kind of; you don’t want it to interfere with the throttle cable, but beyond that it’s positioning isn’t critical.
predator 212....356 cam...ss stock size valves....26 lb springs....stock head....trying to get this carb to work...any advice on main jet size to start with? i have a 150? i think in it now and there is no change in any adjustments on idle speed or air/fuel mixture screws...way too big?
Yeah, 150 is a ton of jet and is likely outside the range of adjustability. I would be starting around a 130-132.5 main jet for the engine you’ve described.
I need a link for that 17 primary jet if possible my dude
I pulled my stock vm 22s 130 out an compared to real mikuni 130 an seems hole is larger on mikuni.
Hey brother I am in Jacksonville Florida. I am having so many problems with my little 200 mini bike. Do you think you could help me get it running? I'd be willing to pay you.
so turning the fuel mixture screw in makes it richer or leaner?
Turning the screw in closes the idle air bleed, resulting in a richer mixture.
@@bahnzai7313 Thanks
Is there a tiny filter in the primary jet. Looks like there is a filter in mine.
The primary jet is a combination jet (metered orifice) and emulsion tube (the little top tube-looking part with the holes on the side.) If you’re talking about the emulsion tube section of the jet, it’s function is not to filter the fuel, but instead to vary the mix (by way of air bleeds) at different vacuum signals, along with emulsifying the idle circuit’s fuel prior to its introduction into the throttle bore.
I've got a 212 with the straight valves. After installing one of these carbs the motor wouldn't start. I had to adjust the screw on the side all the way in but it only will run a few seconds.
It is a 26mm carb. Maybe I should have gone with the 22mm.
It’s really difficult to remotely diagnose carb issues, but I would be checking to make sure the jets are appropriately sized and not plugged, and that there are no air leaks on the manifold. Will the engine run if you hold the throttle open?
Hi, thanks for your video. I ordered an ORIGINAL Japan Mikuni vm 22mm -133 carb I thought... But, when I opened it up to change the Main jet it has a rubber "O" ring on it made with it. I have never seen this kind of a jet in a Mikuni before. Also, looked like instead of a #100 bore it was 250+ bore or more in it in it. I ordered 3 on both side of the Original Mikuni for this vn 22 133 carb and had hex heads which was normal for this model. I was wondering if the Mikuni vm 22mm 13-5000 is a different type of Mikuni and using different jets? Sold by a reputable company with 100# feedback score , list in their add it had all the things the vm22mm 133 carb would have, 100 Main and the 30 slow. I took a look at the invoice and it says SENT : 1 Mikuni vm 22mm 13-5000. Do you know if this is the same as the 133? But, as I said, I have never seen a jet for vm 22mm Mikuni with a Main jet with an "O" ring made into the top of it that seem to go into a place in the bottom of the Bowl where the drain plug is. It must have some purpose or it wouldn't be there on the jet. Now that I have ordered many jets for original Mikuni , hex head, from Mikuni don't know if they are going to work or nor since the one that came has the rubber "O" ring made into the top of it..What is your opinion and or anyone else if they have seen this before? Thanks..Love your channel.
The emulsion tube sometimes has an o-ring; are you sure you’re not taking the tube out along with the main jet?
The main jet on a genuine vm22-133 is behind the 10mm bolt screwed into the float bowl. No need to drop the bowl for a main jet change, just pull that bolt.
I sent my mild built predator stage two with a Chinese Mikuni Carburetor, it runs beautiful all the way up but it stops at 6100 RPM it’s built for 75 so I pulled the plug out and it’s running lean do I need a bigger main jet or can I drop the needle clip
Try moving the needle clip to a lower position; if that doesn’t work, set of back to the lean side and increase the main jet size, and tune from there.
@@bahnzai7313 I sent the carbureted in with the 135 main jet, and my adjustment turned out 2 1/2 turns. I opened up my carburetor it was exactly the same so I put a 125 in and it works absolutely flawless, it was getting too much gas on the high end. Now I got to go deal with that scumbag because he never touched My carburetor and he charged me. He’s the guy that gives the rest of you guys a bad name. Thanks for your help buddy thank you so much
How can I tell if my motor is running lean???
Tuning my 1st carb which happens to be a Mikuni 22. As far as setting the air screw (underneath) I'm hearing 2 ways to set it which is interesting. You advise what's shown here and Mikuni put out a video recommending to set the idle screw at the point where if you turned it another ⅛ of a turn the motor will conk out. You then (starting at 1½ turns out) adjust the air screw both directions until the motor starts to stumble and find the middle point.
My biggest fear is running my built-up motor to lean and melting the piston.
Valid, but unwarranted concern. You’re only adjusting a percentage of the primary jet, at idle, and you’re actually trying to make the mixture perfect. The adjuster screw meters the amount of AIR in the air bleeds, not the amount of fuel, so it’s literally impossible that you would fuel starve the engine playing with the adjuster. Use a tachometer and play with the screw to find the highest rpm mix, and then adjust the idle speed screw again to get the rpms where you want.
Your descriptions of how vm22 works are.. One is left wanting for lack of clarity and concise penmanship.
mine is a different Chinese vm22 but I’m running a 145 jet and it’s dead center in the needle. It runs great too end but I feel like I lost the low end torque compared to the Venturi. 196 18lb springs, mod2 cam,gov removed, exhaust pipe and cone filter. I personally thought that was high but the spark plug is perfect in coloration. Idk. Any thoughts?
Every engine is different, but that seems like a pretty big jet to me too.
@@bahnzai7313 hey my needle is lean at top.cranks good runs good 135 main but my plug is super clean.do I need a bigger main? Or go to the middle on the needle.
Yep! Fuel is just like timing; keep adding it until power drops off, then back it off a click. If I’m tuning without a wideband I like to start on the fat side and go leaner, so maybe just toss a 137.5 in it, middle clip, and lean it on the clip if necessary.
@@bahnzai7313 do you think I should keep going up in jet size an leave my needle clip an mixture screw alone? I t runs an idles good just the plug is so clean .its like no sut or tan color at all.212 ,vm22, flat top, GPS mod 2 cam, 18 lb spring,s ,no gov . is what I have.non hemi . maybe a 140 jet?
Do you have a link to the proper jets?
Niche Cycle Supply- you’ll have to do a visual comparison to see which type jets are in your specific Chikuni
What happens if you lose the plastic washer that's underneath the needle clip? Ive got it idling decent...after stripping out the idle adjustment 🤦♂️. At least it's stuck at a good spot now, but I still get a little bogging when I hit the gas. And my torque converter isn't engaging at lower rpms like it should. Help!
Any spacer under the needle clip effectively lifts the needle up in the emulsion tube, so if it was missing it would make it lean. (More needle in the tube at all times). Also, the plastic ring may serve to seal air from leaking down through the needle orifice, so again, it would contribute to a lean condition. That also may be why you’re having to clamp down the idle screw (because of unmetered air leaking into through that needle opening in the slide).
Regarding the torque converter engagement, it’s actually to your benefit for the engagement to be at a higher point in the torque curve (where the motor is making some power); on our racing karts the clutch doesn’t engage *at all* until around 4,000 rpms! A normal 30 Series Torque Converter should be engaging around 2000 RPM’s; if yours isn’t it may be a worn belt or sticky weights in the driver. Hope that helps, thanks for being a viewer!
@@bahnzai7313 Engagement issue went away after I reseated the carb better. And 10-4 on the plastic washer. It's running good now after returning. Thanks for the tips
If I wanna install a VM22 carb would I need to remove governor?
Yes, the throttle setup would be incompatible with a governor. But, fun is incompatible with a governor too, so yank that junk out of there. It’s easy, I promise.
@@bahnzai7313 wouldn't removing governor ruin engine ? would I have to upgrade other internals of engine ?
No, it won’t necessarily ruin anything, although it will make it possible to run higher RPMs, which definitely can ruin stuff. We turn stock rods 6500+ RPMs on some Spec Kart engines we build, but they’re carefully blueprinted engines. I think of you keep the revs under 5500 you’ll likely be ok, but as always, your mileage may vary and shit does happen.
For something like $65, a billet rod is good insurance.
I just installed a 22mm mukuni, I can't get it to start , any suggestions? I know im getting spark
Turn your drain screw out and see if you're getting gas into the carburetor, the float could be stuck.
I’m having the same problem. I have 125 xpro grom clone . I change the jet to a 110 main jet that’s all . I’m getting gas an spark just not sure if the jet is to small or what . I did touch the needle an I have a stock exhaust. All I really messed with fuel screw not the ideal screw. What should I do .?
My fake mikuni on a stage 2 or 3 ? 22 valve springs, billet rod, champion 1 to 1rockers, 265 cam chrome oly rods, 0.012" head gasket, aluminum
flywheel 5°key.... I'm 2500, feet above sea level. HELP ‼️‼️
I have a 212 hemi with a str8 pipe and a autolite plug I wanna get 1 but I can't find a 130 main jet I was told it won't run fully at full throttle unless I up to a 130 main they said leave the pilot jet alone will this work
You can probably get away with the 15 pilot jet that comes in most kits, but you really do need to swap to a larger main jet or it will be dangerously lean at WOT. Jets for these carbs are easy to find, try Niche Cycle online. You’re probably more in the 125-127.5 jet range based on the mods you’ve described.
I have a 125 I had from a old carb and it fits perfectly and I also move the needle to the last knock at the top so it will sit deapper in the jet
I'm still waiting on my manifold
Will be Honda engine blow up?
Help please!
I got a VM 22 replica for a 125cc Chinisse pit bike.
I have been adjusting the fuel screw at the bottom. With bogging issues not going away.
This is what I have;
Needle clip on 4 groove top to bottom.
Fuel screw 5 turns out, bangs and fire out of the tailpipe. Boggs at 1/4 throttle.
Fuel screw 2 turns out only idles, spits and bangs with throttle. Boggs at 1/4 throttle.
Fuel screw 1.25 turns out , it starts and sort of stays on then it dies, Boggs and 1/8 throttle kills it.
Air screw 1.0 turns, barely turns on and dies.
It idles good, bogging come applying throttle.
I will lean the C clip to see if it makes a difference, but other than that what should I do?
Apologies, I haven’t jetted a VM22 on a 125cc engine; I’d be guessing.
@@bahnzai7313 pretty much what everybody and their momma is using them for these days. because china mad a grom clone and this is the #1 upgrade everybody does. please considder doing a video on it if you have access to the bd125 grom clones
Beg to differ stock (pipe, governor delete) actually running about a 110-125 gotta start down there first
We’ve done a bunch tuning on our dyno, under load, with a wideband, and that’s what we’ve found to work best. Obviously, jetting being relative to air density, engine efficiency and a bunch of other factors, the right jet for here may not be the right jet for everywhere. But thanks for adding that info, it may help someone get dialed in.