jwan

I recently sealed up an air leak in my backplate (Savage 21) which caused my engine to run extremely hot. I had set the needle settings extremely rich to compensate and so after fixing the leak I proceeded to retune the engine. It now runs great and temps are within acceptable limits. There is only one problem. After running for a while (1/4 to half a tank, some times a bit more, but never a full tank), or after extended periods of WOT, the engine cuts out when I release the throttle. Basically I'll just let go, it'll coast for a while, and when it stops it dies. Sometimes it'll idle for a second or two after its stopped. If I don't let go of the throttle and just keep on the throttle it seems to run fine, no sign of it running lean (such as power loss). I checked the temps when this happens, its always at approx 120 C so I know its not over heating, I also made sure that there was smoke when I was driving.

I'm sure its not my idle screw because I can run it normally, starting, stopping, WOT etc without a problem when its going. Which needle could be the problem? Could it be something else entirely (I don't think it's likely since it would run fine before i sealed the leak)?

My HSN is 3.5 turns out, LSN at about 3 turns out, mid is at factory. I've got a GPM pipe which seems to require richer settings, but that's only a guess. I've already done the dual tank mod.

Please help!!!

Thanks

8000ft

check your idle setting. the way that i have done it is to adjust the throttle trim on the radio so as to keep the slide in the carb open enough to idle but not to high to engage the clutch. then turn the idle screw in to keep it at that setting. then back off the radio trim and see if it stays at that idle setting. if the rpms drop, tighten the idle screw a bit more.

jwan

I'll try that a bit later but I don't think that's the problem, on one of the runs I had the trim set so the idle was already quite high and it still stalled. Any other possabilities?