Old yZ 80

[jacob24]

Hi i Just brought an old yz 80 all runs fine till the engine warms up then it start to backfire and splutter.`Piston and rings seem fine.has anyone got any idea on what it could be. any help would be greatly app
cheers jacob

 

[pitmaster]

Make sure you using fresh fuel mix,

New spark plug,

if its old and been sitting for ages, Give carby good clean

could be low compression if its old,

Make sure the Reed Valves arnt cracked etc

 

[jacob24]

Thanks will check it out

 

[mxmad]

if its only sputtering wen hot it could be the air/fuel mixture... Make SURE the bike isnt running lean, if it is the engine will crap itself after sooon.