Originally Posted by
Bai Shen
How do I check the shimming? I got the engine used so I'm not sure what the previous owner was running in it. I thought you only had to retune for nitro changes?
GO engines come shimmed for up to 30% from the factory.
No need for the . 2mm run in shim.
Standard shimming is . 5mm.
Normally 1x . 3 alloy and 1x . 2 copper.
Older motors may have the alloy shim and 2x . 1mm shims instead.
Run a medium plug like the Ok 97T or Werks #6 for best results on 30%.
The GO motors love the higher nitro content.
You will notice a huge difference from the 20% you have been running.
Go with the Byron's fuel - 30 / 9 if you can get it.