dantheman Posted July 23, 2012 Report Posted July 23, 2012 I need some help jetting my 4mill cub,just came back from pismo and wasn't to happy..I have a hesitation when I launch at the drags,almost as if it wants to die off for a second or two, but then it gets going pretty good.it also hesitates to shift gear just for that gear.after that it gets it through all gears...I have read a lot of info on jetting but don't have much experience,my question is what circuit may need attention if not all? What are u guys running for Ur jets on pwk39... My set up is 421 cub 21cc domes 4 mill crank pwk39 on vp110 at sea level..shears oof..current jetting 167mains and 67pilots not sure on the needle position ,bike idles good and rides fine except when i launch?? I know that when banshees are not tuned right the shifting can also b weird. I beleave that's what's confusing me,would that b the mains since I'm at wot?even though my speed hasn't picked up? Any info would b great , thanks in advance Quote
vulvafan537240 Posted July 23, 2012 Report Posted July 23, 2012 Sounds like a huge pilot to me. I run a 52 pilot but that's with 35 pwk's. Quote
wacko2000 Posted July 23, 2012 Report Posted July 23, 2012 Stock cast or ported?? Either way you pilot is huge- 50-55 and main sounds lean! Cubs around here at sea level usually in the 175-185 range Have you done a leak down test? How'd you end up with you current jetting? Joe Quote
dantheman Posted July 23, 2012 Author Report Posted July 23, 2012 Leak down test passed,my builder recommend my current jetting, stage two port on cylinders..thanks for the info.. Quote
possum Posted July 23, 2012 Report Posted July 23, 2012 Just sounds like it cant pull the gearing. Check plugs. Do a plug chop if u need to. But if it runs good rolling into the power. Could be just gearing and or launching ability. Or both. Quote
SonOfSand Posted July 23, 2012 Report Posted July 23, 2012 We need to know your needle, it has a lot to do with 1/8 to 3/4 throttle. Quote
dantheman Posted July 23, 2012 Author Report Posted July 23, 2012 I will check my needle position asap,just wanted to know if I was in the ball park with my jets,I will definitely buy some new jets tho... Quote
SonOfSand Posted July 23, 2012 Report Posted July 23, 2012 I will check my needle position asap,just wanted to know if I was in the ball park with my jets,I will definitely buy some new jets tho... Which needle too? CEL, CEK... Quote
dantheman Posted July 23, 2012 Author Report Posted July 23, 2012 Cel middle clip. Anyone else run similar set ups in dumont, glamis,,?? Quote
dave5.0 Posted July 24, 2012 Report Posted July 24, 2012 I've got a similar setup. Drag ported. Sounds like the pilot is big, main sounds close. Are u runnin a lockup? Quote
dantheman Posted July 24, 2012 Author Report Posted July 24, 2012 Yes lock up,override,,,what pilot are you running? Also where do u ride? Quote
dave5.0 Posted July 24, 2012 Report Posted July 24, 2012 Yes lock up,override,,,what pilot are you running? Also where do u ride? I've got a slingshot lockup. I think I've got it too tight and it bogs because I think I've been dumping it out of the hole instead of feathering it. It runs like a raped ape after it gets going. It's jetted somewhat for little Sahara, OK. I'll have to look at the carbs to tell u exactly where it is though. You'll prob have it figured out before that. Haha Quote
vulvafan537240 Posted July 24, 2012 Report Posted July 24, 2012 What elevation are you at dantheman? Quote
dantheman Posted July 24, 2012 Author Report Posted July 24, 2012 I'm at sea level,I live in los Angeles,ride in dumont and pismo mostly,while we were at pismo we threw in my buddies pwk35s on meth to check if it was the tunning that was causing this prob..we knew he's 35s are dialed in...bike ran awesome...thanks for all the help guys at this point I'm leaning towards my pilots... Quote
werner Posted August 7, 2012 Report Posted August 7, 2012 Sounds rich to me. Try a smaller pilot or move the needle down a notch or two. Also check your a/f screw. Quote
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