I've got a '00 quadrunner 500 and when i run it a long time and cut if off or go fast and slow down quickly it back-fires. Any idea what to do about it? Its idleing fine(not to high), and ive drained the carb one time just to see if its getting to much gas or something, but anyway please help me out. thanks

 

The main jet is probabley alittle lean

 

thanks ill try to adjust it some, didnt think of that

 

ACdude, go to the Tech Threads, here and you will probably get to the root of your problem. But you are not running lean. Sounds like you're too rich or timing is off. Get help from someone who knows small engine repair if possible.
Good luck...
Chuck, Suzuki KQ 300, GPS & lunch...

 

Check your air filter, when they get dirty in my 98 quadrunner the machine tends to backfire, i helped the problem by installing a Uni Filter...

 

If the drain plug for soot is lose or off on the back end of the spark arrester it will backfire. Check to see if these are secure.