help jetting: tb 88cc kit

just bought a TB 88cc kit with the 20mm carb, race head, cylinder, high comp piston, high volume oil pump, cam, rockers, rev box. got it all buttoned up and i cant for the life of me seem to get it jetted correctly. its a crf70 and i tried the 82,85,87,90,92,95 main and it will just bog and pop when it gets up top in the RPM. it runs fine down low and idles but i cant tell if its loading up on gas or not getting enough. dropped the needle one notch and went with the biggest main and it still didnt help. it has the whole kit onto a stock exhaust. anybody else running it like that and have their specs? this thing is frustating me:banghead:

i see a lot of people are saying the needle should be 4th notch from the top, around a 90-95 on the main, 35 pilot, and 1/2 to 3/4 turn out on the air screw but that didnt work at all for me. im stumped. even tried that setting but 1-1/2 turns out on the screw and still nothing

Edited by aids

I have the same exact set up on my 07crf70 except I have a FMF pipe on mine... I have tried every combo of main and pilot jetting I can and still have a bog at about 3/4 throttle. If I roll into the rpms smooth and easy it works through it pretty good but if I accelerate hard it bogs/studders really bad at about 3/4throttle... Even if I just pin it WOT it bogs/pops until it works its way through and then it rips!! I have heard that the foam air filter could be effecting air flow so I ordered a TB K&n style filter to try... The bike bogs much worse with no filter at all and I filled a 8 inch tube onto the carb inlet and it did run better so I could possibly see a filter causing some issue.

I'm interested to see others response and have read thru many of the jetting threads on here and other mini forums.

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