When I say it won't pull, I mean after it warms up to a temperature of around 200 degrees. From start-up to around 175 degrees it will idle and accelerate great. One time it jerked the car from my hand and flew off the end of my work bench. At 200 degrees it will idle (good pinch test results), but when you accelerate it faulters and dies. This is with the high speed needle screwed out to where it is flush with it's housing. The mid range needle is set flush with the case. I noticed when I had the head off that it only had one head shim instead of the two the manual describes. I would not think alittle more compression would cause this problem. The manual talks about resetting the low speed needle to 1 3/4 turns out. This is a very lean condition on my engine. What is a good starting over setting for all three needles? As I stated before, I have had many years of practice tuning nitro engines. This particular engine is a real poser. Everyone else loves these engines and I like O.S. engines also, it may be that I got one of the bad ones from the factory. A few guys here locally are having problems with the front bearings leaking fuel. A trip to the bearing shop usually solves their problems. Aftermarket bearings are usually cheaper than factory bearings and less expensive also.