ur backfireing because ur jettings off..well there could be other things..exhaust leak maybe but its most likely ur jetting, i took my quad in this week and there fixing a front disc break and also checking out my jet kit to make sure they put the rigth jets in because mine backfires as well

 

you could have low antifreeze, faulty temp sensor causing the engine to kill itself (dont quote me on that, dont know if that year even had that option). check your radiator for pinholes. could be the camshaft problem, too. you could have a bad oil injector too.

 

sounds like its running lean, try lowering the clip on the needle in the carb one notch, this will richen the mixture.

 

Hey Younger did you get you problems sorted out?
I picked up a 2000 scrambler 500, sounds like I am having the similar problems
QUAD always starts and runs great for about 1/2 hr then it seems to starve for gas
a bit of sputting and dead. usually takes 1/2 hr to an 1 and boom quad starts up right away
Is this similar to your problem? let me know how you made out, if it's fix?
[img]i/expressions/face-icon-small-confused.gif[/img]
Darren

 

Darren,
The "stalling when hot problem" was fixed by pulling the fuel tank off the bike. I removed and cleaned the fuel valve.....could not believe the amount of dirt I found in the tank collected on the mesh of the fuel valve.

Have you checked the fuel lines yet?

 

You could tell him to weld up that weep hole also since you already gave so much more BS info

 

if his 500 had a weep hole id tell him to weld it shut, thanks.

 

Well his 500 does have the weep hole so perhaps he should find a welder.

 

Hey Younger, yes I pulled the tank off, pulled and clean the fuel valve,
and blew all the gas and air lines out, guess we see,
My shutting down was accuring after about 1/2-45min rides,
Have not taken it out that long yet, hopefully this is the fix.
guess I'll tackel the sensor's if not(thx cornbread)

 

Thx dude, Problem has been gone since I ripped off the tank, and cleaned the FUEL VALVE,
Has not stalled since and have had many 3-4 hrs ride.
Yeah Baby, Keep on Keep'n on!
Happy tails