back firing

[Rick78]

hey my name is Rick, i just got a 2000 gz250 from my neighbor. i cleaned the tank out and cleaned the carb. then bought a new battery for it. it ran perfect for a couple of weeks. now its back firing when slowing down.

[Rick78]

i have a 2000 gz250. that i bought of my neighbor. i cleaned the carb, cleaned the tank out, and got a new battery for it. it ran perfect for a couple of weeks. then it started back firring when slowing down. dont know if its running rich or lean

[blaine]

Originally Posted by Rick78

hey my name is Rick, i just got a 2000 gz250 from my neighbor. i cleaned the tank out and cleaned the carb. then bought a new battery for it. it ran perfect for a couple of weeks. now its back firing when slowing down.

Welcome.It sounds like a little crud still in the carb.The back firing is usually a sign of running lean.Try some SeaFoam or Berrymans b12 in a tank of fresh fuel.You should also install a inline fuel filter if you haven't already.If you adjusted the idle mixture screw,it could be a little lean,turning the screw out makes the mixture richer,turning the screw in is lean.
:cool:

[Rick78]

Thanks, where is the mixture screw? So do you think I should take the carb off and clean it again?

[blaine]

Originally Posted by Rick78

Thanks, where is the mixture screw? So do you think I should take the carb off and clean it again?

The mixture screw is in front of the float bowl.It may have a plug in it from the factory,if someone hasn't removed it.If you haven't touched it,than dirt is your likely problem.The carb cleaner may do the trick and save you taking the carb off again.If you want to access the idle mixture screw to adjust it or drill out the factory plug,than you need to remove the carb.There is a good diagram of the carb on page 4-3 in the manual witch can be downloaded here.
viewtopic.php?f=3&t=27

[Rick78]

Thanks again. Yeah, the carb is all stock. And the bike was ranning good before. So you don't have to take the carb off to clean it then? Because last time I took the whole carb off and let it soke in carb cleaner

[blaine]

Originally Posted by Rick78

Thanks again. Yeah, the carb is all stock. And the bike was ranning good before. So you don't have to take the carb off to clean it then? Because last time I took the whole carb off and let it soke in carb cleaner

I would try some carb cleaner first,it should help. :cool:

[jonathan180iq]

Topics merged and moved to Troubleshooting.