Originally posted by rodneybarrett
ok. still having problems with the engine. I have tried the different needle settings but they made the bottom end way too lean.
The crank is normal and wont cause you problems. How did you determine that the bottom end was too lean?
Have you tried what I have suggested above:
Do the pinch test I provided above first. If this is OK, then richen up the top end so when you pull WOT it does not pull maximum RPM then start leaning it again while checking performance on the track. Run it for a while and check the temps. If this is all OK then you likely have some form of mechanical issue.
If you do this you cannot get the tune wrong it is impossible. Running 30% fuel makes tuning more delicate. Start from rich and follow the procedure I outlined. I am no nitro genius and I get my motors tuned perfectly. This is also the proceedure that Josh Cyrul recommends. Forget about the temps for the moment, get the motor running so it sounds and reacts correctly. Then let the motor cool down and run it. If it is getting too hot at that point you need to:
1. Check the clutch is set right.
2. Ensure your fuel is good quality (I dont know that fuel you are using)
3. Add head shims.
4. Check for air leaks.