Alright, I bought a NEO .16 engine for my Nitro Evader. The first 5 tanks of break-in went by great. The engine has loads of compression, but usually started on the first or second pull. After the 5th tank, things began to turn sour and eventually I heard a little knocking and thought I toasted the rod or something. Closer inspection revealed that the backplate had loosened up far enough that the shaft sticking out of it slid off the crank completely. I looked inside the engine and everything looks great. It's still nice and shiny, and there were no problems cause by the shaft that I could see. I put it back together (with a generous application of thread locker) and it seems like it really has a hard time finding a tune.

It wont start sometimes, and then I richen the low speed needle and it starts. I then rev it up high to clear it all out, and when I let off it dies. Everything is plenty rich, but not overly so, because when I tried to lean it rather than richen it, it wouldn't even give me the chance to rev it up. It has the revving and dying problem with the wheels off the ground as well, so I no it isn't a clutch problem. I don't understand it at all. Could it be just some weird carburetor problem? It makes me so mad because the engine has so much compression and ran so reliably during the first 5 tanks. The temps on it were always fine. I just bought this engine and it has me totally confused. I have went some 3 years without ever having a problem out of a nitro engine that I couldn't fix myself, but this one has me flat out stumped. I need some help bad.