at 1st I thought it was just a stumble in mid rpms. but I found it to be all over.

decided to try the vforce reeds and 26mm mikuni round slide before buying a set of boyesen reeds for it and I noticed the stumble... played with jetting rich and lean, didn't seem to help.

so I decided to put the stocker back on, the stumble was still there.. then I decide to play with jetting, didn't help rich and lean...

changed plugs. didn't help.

noticed head gasket looked like it had a slight leak so I changed it.

thought maybe the crank seal so I pulled the fan cover then fan and didn't see fluid and looked to make sure timing was still aligned on the stator and it was...

thinking tomorrow I'll ohm the stator and try a different coil... then soapy water and look for a bottom end leak somewhere...

I have a milled head on it mid west mini speed/power package less the reeds as I had the 26mm mikuni on it when I bought the bike..

also will be checking the tranny fluid but I think its the engine stumbling not just tranny area. I did bake it in my grill and have fluid come out and forgot to fill it... we'll see, lots of things to check from lol

could potentially be a long day tomorrow...

also what kind of fluid do you guys use for the rear gearing standard gear oil? I can't find my service/repair manual

can't wait to get it all dialed in again... seemed like it was pulling like a **** with the vforce and 26mm carb on it. lifted up the nose like nothing... ordered a 14t yz80/rm80/85 countershaft sprocket as well so it'll have better top speed when it's running good lol.

will also be looking at getting some porting and raising the stall when it's running top shape oh, and narrower tires like some 18x6.5" snow hogs front and rear and see if she rips more (less rotational mass than these 10.5" wide rear tires I have on it now). get a set of 16.5x6.5"s for the track too while I'm at it, or maybe just get the 18"s for front and 16.5"s for rear... but I want to get the issues all worked out and get her screaming again

 

stator checks out

 

only does it under load (someone riding it)

I put it on a tire and it revved up to full rpms no hesitations... not sure what the problem is at this point... gonna pop open the CVT side I suppose but I don't think I'll find anything

 

what's the compression?

 

115psi... for a milled head that sounds kinda low

also, the gear oil spilled out before/during the last teardown and I forgot to fill it. there wasn't alot in there and it was black and silvery lmfao. I drained it and filled it with motorex 10-40 semi synthetic... still doing it tho so that didn't help either...

my bikes are different 1st gen/2nd gen the one having issues is an 04 the other is older with no CDI so I can't just swap coils as I innitially thought but I mean. spark won't change under heavy load would it? I can pretty much rule out fuel as a problem as it did it with two different carbs/reed cage setups. the large 26mm w/v force reed cage setup w/performance reeds as well as the stock carb/reed cage/reed setup... I run a clear fuel line and there is no problems with flow to the carbs...

 

oh, the entire bike jerks when it does it. when I talked to my buddy he said it DID sound like it could be the tranny...

 

all gears look fine, no chipped or missing teeth

I guess it's back to the motor...

I suppose it could be the crank... I didn't find any leaks.