MOPED ARMY

<why do i backfire?>

Too many 7-11 Burritos????

Can you explain what you mean by backfire?

A backfire is when burning mixture jets out of the carburetor & intake.. if it's a loud bang from the exhaust, that's something different - the charge is exploding in the pipe. Some people call this an 'exhaust backfire' but it's a weak use of the term.

Which one is it?

joew,

That is ... just plain wrong. Lol.

I'll take the baked beans, but I'll pass on the cottage cheese.

larry and joe have it right,i cant adjust the cdi but if i did it would have no impact.its a motor from a korado on a magnum with an airsal kit and a 15 mm amal.from 0-10 its normal then 10-30 its fucking great then after that its sucking.i dont know where to go from here.ive put the mixture screw in alot of different positions but still no avail.im lost except from the jet thing but a 60 is too big.i might just buy everything between a 45 and 60 and then bitch after when i feel i have a reason

It sounds like your unit is four-stroking from running too rich at top end.

This can be causes by the jet being too big or that the air filter is too restrictive. It is also possible that you will need a larger carb.

Try one jet size down but be carefull to do your plug chops. You do not want to sieze the engine.

Check your timing. It could be too advanced.

Also: have you done any porting work? You could have too much overlap. The pulses in the pipe could be drawing all the fresh gas charge out into the exhaust.