Need help with engine (Gonna stump ya)

[Mnster]

Hey I'm a lurker I check this board everyday at least once since I joined. I don't usually post because I'm more into rock crawlers than anything else. But I seem to have engine problems on my Losi XXX-nt. The engine is a Nova rossi CX .12 non-pullstart race engine with slide carb. I drove it until last fall when I was romping through a very dusty bmx style jump course. The air filter came off and sucked tons of dust into the engine. So I disassebled the entire engine and removed every last scrap of dust. I sent the sleeve and piston away to get honed, polished, and resized. It came back like new I installed it in the engine, I lubed it with after run. I put a new glow plug in, cleaned the carb and set the needles to the factory specs. Oiled and put a new air filter element on. So new engine right? I can get it started but I can even idle through a tank. It just runs for a little bit then sputters and dies I thought maybe it was my tuning so I riched the high speed needle up a little. When its rich I can see a mist of fuel spraying out the pipe. Leaning the engine out does not fix anything but the fuel spray. I played with the idle screw for a while didn't seem to fix it. I though you know what? Maybe my nitro is old so today I went and picked up a new gallon of 20%, no luck. Also it seems to get really hot before it dies. I've checked the engine over several times and I can't figure it out.
I need Help!

[bubbacola]

I had a .21 do something like that . It was the muffer. hole was cloded and no pressure to fuel tank. it would die just above idel

[HAGASAN]

Who did you send the piston and sleeve to? And was it modded? Did you put all the head shims back in? Are you using the same bearings and if so, when you had the motor apart, could you move the bearings very freely with absoluty no "feeling" of dirt or knicked bearings? IS the clutch installed correctly?

[Mr. Tune]

Do you adjust the LSN? It'll give you those symptoms if it's set too lean.