ok guys i have been using 13 g rollers with gilera runner air box and 25mm carb .The bike holds a steady rev of 7500 rpm all the way to top speed .I removed the air box and rejetted the carb .no on pull of it revs to 7500 rpm then drops to about 7100 (egine relaxes) the rev back up to 8000 rpm .I thought is the engine is now making more power and going up in the gears too fast causing this behavior and roller weights needs to be dropped a bit.Can i get some imputs please
It may be the belt slipping - are you on a standard contra spring? If so, I'd maybe go for a stronger contra spring in the clutch, to ensure that the belt stays gripped. Generally, if you lighten the rollers, you'll make the problem worse unless you use a lighter contra spring.