I just bought my first Nitro truck which was a HPI Nitro MT with the Nitrostar .15FE engine. My problem is that I can't seem to get the engine to idle for anything longer than a couple minutes at a time. I tried to break the engine in according to the manual, but I couldn't get it to idle very long. Is this normal? The car runs awesome otherwise. Tons of power and speed, it just won't idle on it's own. Thanks for any input or help...

try messin with some of the needles, like the idle speed needle

Yeah, this engine is pretty simple...only one needle adjustment. I started at three-turns out and am running it now at 2 1/2 but the problem remains. Runs great, just won't really idle. Do you think that would be cause by too rich?

your running too lean.. your engine is over heating...
... turns in.. is running lean.. turns out.. is running rich ... engine cuts out if you run to lean.. overheats...

The 15FE is really a pretty simple engine. At 2 1/2 turns out, I would doubt that you were running it too lean! I ran mine at 2 to 2 1/2 turns out and it performed well through 3 to 4 gallons of fuel before I sold it. One of the problems with the NMT is that at idle, it vibrates like crazy. If I let mine idle for too terribly long, the fuel would start to foam and I'd get air bubbles in the line. End result was that it would stall.

Another thing you may want to look for is an air leak in one of the lines or at the base of the carb. Also check to see if the gas tank lid is sealing properly. If it's not, the fuel system doesn't build up the necessary pressure required to make everything operate properly. Lastly, check to see what temp you're running at. Anything over 250 is too hot for the 15FE.

oh forgot..... my engine has at least over 2 gallons through it.. it's very bad in compression.. .. it also depends on the day and where you live.. where I live.. it's pretty humid.. so.. blarghes!...

blarghes? dare I ask?

no need to ask.. fustration... I bumped up my nitro percentage.. and it idles way better... I think it's because I'm using slightly old fuel.. it feels like a rocket compared to how sluggish it used to run.

Thanks for the replies, guys! I was reading what you wrote, dagass, and it made sense. It didn't sound like to lean. I actually leaned it out a little more and it idles much longer before dying. Not perfect, but it's pretty new still and I'm afraid to lean it out much more. The temps are a little cold, but once I get a gallon or so through I will lean it out a little more. I think eventually the problem will go away with tuning.