HOW TO - Change the main jet in your Wolverine 350

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wolverine350rider

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(100% of the credit goes to "Glenn" At Northeastatvers.com) I just thought this could be helpful, it sure helped me out.


This write up will highlight how to change the main jet on your carburetor without removing your carburetor from your machine. In my case, upping the main jet is all that is needed to compensate for an aftermarket pipe and filter. Some machines may require upping the main and playing with the needle. For now, we'll just deal with swapping out main jets.

Depending on how your machine is set up, you may want to remove the fuel line for easier access to the carb.

Pic 1- Loosening the carb...engine side. I had the airbox removed for another project, but it did makes things easier. If you don't remove your airbox, make sure you loosen the clamp on the air box side, as well as the engine side.

Pic 2- Once that's taken care of, slowly rotate the carb 90 degrees so the bottom of the bowl is facing you. Do this slowly so you don't kink or tweak any cables or wiring that may be around the carb. It's also a good idea to put down some rags or paper towels to collect any fuel that will spill out of the bowl.



Note: The dump screw on my carb didn't have the hose attached to it. Usually, you can shut off the fuel at the petcock, open the dump screw and catch any gas that drains from the carb. Without the hose, I used the paper towels to catch any gasoline that came out when I slowly loosened the 4 screws holding the bowl to the carb body.


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Pic 1- Remove the 4 screws holding the bowl to the carb body. Some fuel may spill out here. Once you have the screws removed, pull off the bowl. Next, carefully unscrew the main jet.

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Pic 2- While you have the bowl removed, clean it out with some carb cleaner. If you look closely, you can see some stuff in the lower righthand corner of the bowl.

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After the bowl is clean, it's time to install the new jet. Install the new main and snug it up. Don't crank the thing down too tightly; you don't want to damage the carb body! Just tighten it until it's snug. Once you have the jet in, you can reinstall the bowl. I used a little anti seize on the screws to facilitate removal in the future.

Button everything up, start the quad and take it for a ride

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Once again- (100% of the credit goes to "Glenn" At Northeastatvers.com) I just thought this could be helpful, it sure helped me out.
 
Re: DUH!

Wolvy Wood Pecker said:
Most jet kits require to change needle and oversize the 2 holes of the carb slide....

I just replaced the main jet, and it runs perfect.
 
I just jetted my card and only had to drill one hole in the carb slide should i have drilled out both? I am using the dyonjet system and with a 160 jet. Help me out did i do this right?
 
Just jetted my card and only had to drill one hole in the carb slide should i have drilled out both? I am using the dyonjet system and with a 160 jet. Help me out did i do this right?
Which hole did you drill?, the one in the center of the slide doesnt have to be drilled but can be if you wish. The offset hole should be drilled.
 
Anybody checking the plug for color? Or, are you just going by performance? Right now, with intake mod and exhaust my bike runs great but the plug is not tan like it should be. It's leaning towards gray, dark gray. Not white like super lean but still not brown, tan as it should be. Any input is greatly appreciated.

Machete <><
 
Machete - you are on the edge. I say that as you most likely already know, you are after that hint of tan. Dark Grey comes before light grey which comes before white - white is meltdown time.

Anyway, as the temperatures continue to warm up, your machine will continue to run a bit richer and richer. This is good as you most likley won't be required to change your jetting - richer = cooler = good.

Now, when winter comes, you'll need to start paying attention - as you never want to head to a lighter color than you are at right now.

Another good thing is that as your air filter becomes dirtier, you'll start using more fuel which will help richen the mixture yet again.
 
nice info!!! i'm thinking of the HMF Sport slip on, re-jet and filter. should i just change the main jet? or should i change the needle and pilot jet too? anyone have any suggestions?
 
great post! I printed it out and tried it to my 350 with the HMF. I changed the main jet to 160 like the direction said and turned the screw 2 and a half turns out. I couldn't figure out what to do with the needle or what hole to drill out, the directions had a diagram but couldn't make heads or tails of it!! ( NEED PHOTOS). I rode it the next day and it ran better than the stock jetting except for a bobble when I let off the throttle. Any tips on what I did wrong??!
 
boomsling said:
nice info!!! i'm thinking of the HMF Sport slip on, re-jet and filter. should i just change the main jet? or should i change the needle and pilot jet too? anyone have any suggestions?

Im running the HMF Slip-on, CFM airbox (running with no lid), Uni-filter, and I am running a DJ 155 main.
 
Can anybody tell me what size you are drilling the slide out to and what is the stock size. Is it #48. I did mine and did not write down the stock number.
 
i just got my 99 wolvy and it has a bad dead spot right off idle.the guy before me said he had put a dyno jet kit in it,but something is totally wrong.im not really sure what he has actually done and he could not clear up the confusion at all.has anyone else had this problem,or have a suggestion to fix it?
 
Wolverine350rider - I found with my 450 that I had to undo all but the throttle linkage in order to be able to turn the carb 90 degrees...also had the shift bar on one side and the headpipe on the other so it made things a bit more tricky.

All - HMF website as Glenn mentions recommends just replacing the stock main which I think was a 131.5 on my 450, my eyes aint what they used to be, with a 140. I did this tonight and all seems well so far. Going on a test ride this weekend and will post my results following.

mfrench95 - before I changed the jet tonight I cruzed around the forums on HMF's website... lots of good info including which jet is responsible for which part of the throttle...I believe the pilot/slow jet is the one responsible for off idle to 1/4 throttle. Check out the post called Carb 101

http://hmfracing.com/forums/showthread.php?t=497
 
Okay, kinda afraid to do this myself. Is it as hard as it seems?
I got the Dynojet kit and my HMF slipon but really hesitant to do carb work
that I'm not familiar with.
 
It's very simple, you have nothing to worry about. :)
 

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