new banshee owner and member. need help

[medley]

i just bought a 1998 banshee. it has poor throttle response and bogs when given gas while idlieing (free reving). also it feels like it doesnt have much of a power band and doesnt even try to pull the front wheels off the ground in first gear. it has a cool head 21cc domes, fresh motor .040 over,wiseco crank and pistons, v force 3 with carbon fiber reeds, 28mm keihin carbs with jjh needles on middle notch, 155 mains and 50 pilots, full toomey t-6 exhaust and the air box has 6 1inch holes drilled in the top. i have been trying to get this figured out all week and cant find the problem. i put a new set of clutches in because i thought they were slipping when the power came on but that didnt help. the gearing on it is 13/40. my elevation is also around 650ft above sea level. any help would be greatly appreciated

Edited November 20, 2011 by medley

[Larry's Shee]

Welcome to BHQ !! Fresh fuel mix? Air filter clean? New plugs (or what do they look like?) Clean carbs and set float level. Look to see if you have adj timing plate, if so make sure it's advanced not retarded.

[medley]

Filter is clean. Carbs look clean but I'll pull them apart. I havent checked for a timming plate. That was my next step today was to pull the flywheel off and see if it had one or sheared the key.

[medley]

Not sure how fresh the fuel is, it was already mixed when I got the bike last week. He said its mixed 32:1.not sure if it matters but the end of the exhaust is wet and black like it is rich.

[medley]

Compression is 160psi in each cylinder. How many should you kick it to get an accurate compression reading? I can also read the part numbers on top of the pistons and there clean so I know its a fresh build.

[Jereme6655]

you should be holding WOT and kick until the guage stops going up.....if it takes 3 or 8 kicks.....kick til it stops. clean pistons can also be from a coolant leak....it will steam wash your piston tops......but you'd see some scuffing on the pistons if you pulled them out.

 

160 is pretty high.....definaately high enough thtat i'd be worried that 93octane woulnd't support it.....you may have to run 100

[medley]

I kicked it it until the gauge didnt go up anymore. The guy I got it from told me "dont.not run race gas, it will fry the pistons. It was built for pump gas." Could that be my problem is it might need 100+ octane? Or could it be rich?

[medley]

I done the compression test after I warmed the bike up.

[BigRed350x]

160psi static is above the general lever where folks start suggesting race gas. 150-155psi is usually a good base-line mark for where you need to start switching over or running a 50/50 mix of race-gas and pump gas. Add timing advace in with that and you definitely need to run a higher octane fuel. If you are at 160 and have any timing advace I would suggest running a 50/50mix of race-gas and pump-gas.

 

As for the bogging and poor performance, its probably just a jetting issue. I would start by replacing your gas with stuff YOU know is good and mixed correctly. Stator and coil problems can also present themselves as a bog. intermittent spark or poor spark quality will make it run like crap.

 

- Jared

[medley]

I just talked to the previous owner and he said it had adjustable timmimg plate. If the timmimg is retarded would it cause these problems? And if it is running rich and I switch over too race gas would I still have too jet it down? I know when you retard the timming in cars there real sluggish. How do I test the stator too see if that might be the problem?

[medley]

I just talked to the previous owner and he said it had adjustable timmimg plate. If the timmimg is retarded would it cause these problems? And if it is running rich and I switch over too race gas would I still have too jet it down? I know when you retard the timming in cars there real sluggish. How do I test the stator too see if that might be the problem?