OS Four Stroke needle settings
Hi all, I hope someone could enlighten me on some not so average needle settings. I have 2 OS Fs 90s. One the high speed needle has to be set completely closed for it to run at peak rpm. If you open it at all it just slobbers. I have only run this motor on test stand because I am not confident with it in the air. The other 90 runs best at 2 1/8th turn out. I also have a 91 surpass that has to be closed off on the high speed to run at peak. The needles look fine in the two problem motors But I thought I had read somewhere that the needle is two piece and that the actual needle could be pushed back inside the adjusting portion of the needle. any help would be appreciated.