Hi there, a friend gave me his quad in which has been sitting for two years. his complaint was that the manifold was glowing red hot, like red hot. i checked the rad vents, fluids, etc. and then took out the carb and cleaned it fully. it;s back together, but he still hasn't found his manual for me, and i don't know what the two top side tubes are for (up buy the top diaphragm). they don't seem to be vacume tubes, and do they just hang down?(there were a few of us with our hands on this when taking the carb off) or hooked up to something?. The atv will start, but won't idle until the choke is all the way out. The air screw has been set to a standard 1 and 1/4 turns out but seems to do better at only a half turn out. it will idle but when hitting the throttle, it bogs down and stalls....sounds like a main jet to me. If i had the manual, id be able to set the floats to spec, and see the parts for all the jets. it does backfire a bit, and i can see flames come up into the venturi when hitting the throttle. i really would like to know about those two top side tubes. the plugs are not fouled, and used 91 gas. hope to hear back from anyone who has the experience thanx.