carb or timing
Out of time or a burnt valve
Guess you need to rebuilt the carburetor
yes, backfiring is always due to ignition or timing problems. Backfiring through the carb can be a symptom of a lean condition.
Either the timing is excessively retarded or you have a worn camshaft or related problem.
Loss of power, smoke, knocking noise, popping noise, backfiring through carb, or out tailpipe. Any, or, all of these.
When an engine is "spitting back" through the carburetor, it typically indicates an issue with the air-fuel mixture or timing, causing combustion to occur in the intake tract instead of the combustion chamber. This phenomenon is often due to an overly rich mixture, incorrect ignition timing, or a malfunctioning carburetor. In contrast, backfiring refers to combustion occurring in the exhaust system, which can happen due to unburned fuel igniting late in the exhaust cycle. Thus, spitting back through the carb is a sign of intake-related issues, while backfiring pertains to problems in the exhaust system.
well it all depends on when it is backfiring most of the time on start up if it does back fire then it prob because when you turned it off you had the rpms high and sum gass was mostlikely left in the carb
It's lean. Could be a lot of reasons why. Start with the vacuum lines, then the timing, carb, fuel pump, intake gaskets, etc. Look for anything worn or leaking and fix it.
No idea why those problems would suddenly arise after an oil change, but the problem is definately carb related. I would suggest tweaking your fuel-air mixture screw as it sounds like your bike could be running to lean.
after rebuiling carb jet have 2 b adjusted, check ur timing also If you have any exhaust leaks close to the engine it will promote backfires.
water in gas or out of time change the spark plug and check the carb bowl for water if there is then drain the tank and clean the carb Additional comment: Often when you have a motorcycle or ATV that is backfiring you will find that your bike is having a problem with bad spark timing. This will also cause your Jerking... Take your bike to a profession and have them look at the carburetor adjustment and the timing.