New to the forum, live in south west wales. My prob is I have a mallossi 166 kit fitted,24/24 si carb running on a 120 main jet ,200 gears with T5 4th gearing set up, cosa clutch, crank cut and cylinder poarted and matched, put a new lml side engine case with built in lml reed opining with lml reed valves pre mix 3%. I had engine running fine with simonni exhaust with real good speed top and pull. The exhaust is sounding bit old now. Then just recently I have a problem with the revs on it, it does not die back down to tick over it has a delay in dying down. Also I have had a prob when ridding and I hit around 65mph the engine seems to die., I sure it was not a piston seize as wheel did not lock. If any body has any ideas I'd be very greatfull as I hate being of the road and don't want to go leaving the problem and things getting woarse. I have had some one suggest an air leak in the carb? Thanks for reading and happy scootering darren. Oh also would any one recomend running a koso 30mil carb on the scoot, as have brand new one which I bought to fit but would be good to hear any body elses thoughts on it.