OS .91 2 and 4 stroke. But please feel free to pass on your knowledge that you have. I am not to proud to admit that I am wrong and if I am please let me know. I will respect your opinion. Knowledge is something to be passed on. There is not one person that knows everything or even close to that about any one thing.
Your knowledge is valued and needed so please jump on in. By the way, I didn't mean most just been a long day at the shop and field.
Happy landings,
The Doc