Top End Rebuild BackFiring

[dodgextreme4x4]

I bought a 98 blaster and it needed a top end rebuild. So i had the jug bored and bought a new wsm piston, and cleaned the carb. I put it all back together and i ran fine for the first half a tank of gas mixing 32.1. running 93 octane. First i noticed it was kind of slugish then the motor started backfiring and stalling. Dont know whats wrong with it need advice. It has fmf pipes and bosen reeds. thanks

 

[sr5bidder]

have you tried a new plug?
mine was having issues/back fire starting after rebuild and a fresh plug cleared it up

 

[dodgextreme4x4]

It has a brand new plug

 

[fioz600r]

Did you break it in properly after the rebuild? Have you checked the keyway to see if it broke?

 

[wheelspinner]

also if you rebuilt the motor cause it blew up check the bottom of your engine case for cracks that happend to me and i couldn't figure out why it ran so bad till i saw a oily puddle under the quad.

 

[2strokesmoke]

assuming everthing is tightened up properly that you put back on ie head/cylinder bolts and nuts, try the old plug you took out, check the reeds are ok and check the key for the flywheel on the crank like someone else said, ive read on here they are common to go.

 

[quadsrus1]

assuming everthing is tightened up properly that you put back on ie head/cylinder bolts and nuts, try the old plug you took out, check the reeds are ok and check the key for the flywheel on the crank like someone else said, ive read on here they are common to go.

OK now would you happen to know what the Head/Cylinder Nuts are supposed to be torqued at i am in the process of a rebuild?

 

[Prime]

Base nuts are supposed to be 18lbs. and head nuts get torqued to 20lbs.

Also, are you sure you installed the piston correctly? You could have installed it backwards....