93 xr250r Carb or Electrical problems?

[1NASTY1]

I have talked to everybody I know and all the service techs I can call. Nobody seems to have any idea for my problem. I thought this might be the place to get answers. I've got a 93 xr250r. It starts easy and runs good for about 20 to 30 mins. Then when it warms up it wont hardly run over quarter throttle. It wont actually die. It idles good but if you hold it open it bogs and backfires. I have cleaned the carb, it looks good. Im not to sure about the jetting and stuff. I've changed the plug twice. Its usually black and a little damp. Could it be electrical?

 

[kaboom1371]

back firing is usally a timing issue..not real familiar with 4t but posibly valves out of adjustment.

 

[1NASTY1]

It only does the backfiring if your sitting still and hold it wide open. It even shot a little flame out the exhaust today. But if your trying to ride it. It does ok for about a quarter throttle through all the gears. If you hold it open whil riding it mostly bogs and sputters. But if it was a timing issue wouldnt it do it all the time?

 

[_JOE_]

Check the valve clearances, rule that out first.

 

[1NASTY1]

Allright, that is something I havnt done yet. I will give it a shot. Thanks for the reply. I will let ya know how it goes.