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throttle/jetting help
Posted: Sat Apr 06, 2013 5:10 pm
by solitaire1
When I ride around at half or three quarter throttle bike runs fine. When I go wot it still goes but seems to lose power. It also kinda makes a burbling noise.
This is on a sym block, 28 oko, contessa bore, v8 pipe.
Jets are 55/135 with oko air box. Anyone have any ideas?
Re: throttle/jetting help
Posted: Sat Apr 06, 2013 5:32 pm
by bakaracer
main to big if it burbles at wot. make sure the filtet is clean too.
Re: throttle/jetting help
Posted: Sat Apr 06, 2013 6:30 pm
by solitaire1
Ok I'll go try down jetting it. Do need to adjust the needle or anything else while I'm in their?
Re: throttle/jetting help
Posted: Sat Apr 06, 2013 9:06 pm
by bakaracer
if throttle response is good from 1/4-3/4 , no.
Re: throttle/jetting help
Posted: Mon Apr 08, 2013 5:59 pm
by solitaire1
Cleaned filter out, wasn't to dirty. Tried down jetting to 130 and 132. Did the same thing at WOT , just no burble noise. I did notice though at all 3 jet sizes if I WOT from dead stop it pulls fine, but if I WOT from a rolling start it loses power. Throttle response with the 2 smaller jets also feels sloppy at 1/2 - 3/4 throttle. At 135 jet everything except WOT feels really crisp and responsive.
Re: throttle/jetting help
Posted: Mon Apr 08, 2013 11:32 pm
by bakaracer
then sounds like either rollers are to heavy or center spring is dead or not stiff enough
Re: throttle/jetting help
Posted: Tue Apr 09, 2013 12:29 am
by solitaire1
Trans setup is : stock flywheel
lightened Keli pulley
SEF ramp plate
8 1/2 gram weights
stock belt ( fat tooth one)
Keli heavy clutch
15% center spring
2000 rpm shoe springs
All parts except flywheel are new. Had lighter weights before but was way too revvy. Clutch setup is brand new , just moved to a slightly hilly area so needed a bit more low end. I'm begining to think my pulley maybe part of the problem. Could it be too light ? Pulley weight is 130 grams.
Re: throttle/jetting help
Posted: Tue Apr 09, 2013 12:44 pm
by bakaracer
nope! unless the the brass insert where the boss sits is worn out. then it can hang up and not retract back to the position it needs to be at as you decel.if its tight and the boss diesnt rattle in there than its either centet spring is dead or rollers to heavy
Re: throttle/jetting help
Posted: Tue Apr 16, 2013 7:59 pm
by solitaire1
Still couldn't figure out what was wrong. Stripped everything out, replaced lightened pulley with regular helicopter. Cleaned Carb,mani, jets. Rechecked throttle line and quick throttle. Put everything back together. Works great again.