Backfiring and low power

[blaster98]

I just rebuilt the top end, new reeds, new plug, fresh gas. Air box lid is on and hole is plugged on the bottom of box. When I ride at idle to half throttle it's fine after that it acts up. I have stock settings in carb.(which I cleaned also) after half throttle to full, it sometimes backfires and seems low in power.Any suggestions.

 

[Blasterdude27]

Any new mods? Make sure everything was put back together right.

 

[blaster98]

Stock pipe and silencer no other mods. Air leak? Electric?

 

[lassek]

Maybe TORS.....

 

[TheWalkingPlague]

wouldn't he need to break in the new rebuild? I thought i read that on here somewhere.

 

[blaster98]

The plug on the bottom of air box came off, put that back on, and stopped the backfiring. Now it fouls plugs, black and it's boggy. I have 230 main, I guess I'll move the needle to see what happens.

 

[darealblaster]

did you properly do a break in on the new top end?

 

[blaster98]

Yes, I broke it in proper.

 

[custom2stroke]

backfiring is usually a sign of being lean and now you plugged the hole and reduced airflow so it could be getting too much gas to air ratio now. sounds like you need to adjust the carb. change one circuit at a time to see if it gets better or worse. If it's only messing up from half to full it could be a combination of the needle and main jet giving you problems.

 

[specialized7]

maybe the piston is in backwards

 

[custom2stroke]

maybe the piston is in backwards

I would laugh if that came up again.

 

[blaster99]

i think u put the piston in backwards

 

[blaster98]

I got it running good, bad coil.