Hello, I bought a 99 250 quadrunner that smoked like a fright train, I did a top end rebuild and no more smoke. But befor I did the rebuild it wouldn't idle but otherwise ran fine, I chalked it up to plug fouling out from burning oil but that's not the case anymore. You start it up with choke, take choke off after 30 sec or so and it idles beautifully for about 30 seconds then slowly bogs down and dies unless you hit the throttle. I've checked valve clearance, and bypassed the fuel pump by hooking the carb line directly to petcock and running on pri. Same issue. Also no fuel in any vacuum lines. I just went through the carb as well. No change. I'm stumped what else should I check?