CPI SX 50 Problems

[Haayess]

basically, i have a CPI SX 50 2006, my bikes been fine for the past 4 months.. and then everything went wrong! For starters it dies randomly, and then you are unable to kick start or bump start. I had the chains and sprockets changed from a 62 to a 52 and its see med to mess up the gearing.. how easy is it to tune a CPI? also can anybody reccomend a Performance Exhaust?

Last, by not least. I have had this problem where my bike lags through every gear, and i have to keep the revs up high or else i would not be able to pull away. also at around 8,000 revs a loud, peircing, scratching sound comes from the exhaust. could this be the baffles from the exhaust? Please let me know if you have any ideas.

[JonnyFoxtrot]

When is it dying randomly? At idle/come to a stop? At full acceleration while your going along? An answer will depend a lot on where its happening in the ride.

The lag in the gears and the peircing sound from the exhaust sounds like one of several things: either the fuel mixture is off and your either running lean or rich to the point the bike is also dying OR (and probably more suspect) you have an air/vacuum leak somewhere in the air/exhaust system OR the engine is being starved of fuel from the carbs mid ride.

Have a look at a few of these and let us know the results
____________________
'89 Honda NS125F (SOLD) -> '92 Suzuki GS500E (SOLD) -> '03 Kawasaki ZX6R B1H (SOLD) -> '96 VFR 750 RC36 (SOLD) -> '02 Honda CBR1100XX Blackbird