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?