Off the 2 stroke and on the 4 stroke. I just picked up a 99 wr400 last saturday. I got a deal on it as it will not idle. I took a chance that it is something simple. The bike has been sitting for 5 months and fired up first kick but will not idle. Sounds to me like the pilot jet circuit, I cleaned it out but no good. I will also check the throttle shaft adjustment. I checked the tps setting also, all looks good. The bike will let out a couple of backfires out the carb when bringing it down to an idle then dies. Any other ideas as I have done the search thing. The bike only has 1638 kms.