cold sound+backfiring

[robbo23]

hi guys i just bought an atomik 125cc 2nd hand, i believe its about 2 years old, i put premium fuel in it and it has started backfiring and running as if it was cold ever since can someone help.cheers

 

[s2rt24]

clean the carby change the spark plug.

 

[Satchy]

Better check valve clearances while your at it...

 

[nafe]

premium fuel? how premium ? did you put v-power racing in it i think thats like 100 octane, and theres only a couple servos that sell it. The higher octane could be doing some funny buisness in the motor but i doubt thats your problem.

Best just to change to regular fuel when trouble shooting - less variables in the equation the easier it is to work out

Check your valve clearances, spark plug (dont stuff around with chink crap just get a ngk its only $3.50) and clean your carby, if the problem is still there which i doubt you might have to look deeper into the engine.