Thank you for your reply. This is a brand new engine. I broke it in on a test stand. When doing this, I had a lot of smoke coming out the muffler. I assumed it was very rich. I used Power Master FAI. fuel, which is recommemded, Brand New fuel. The engine seemed lean to me, even though it was smoking out the exhaust.
When I prime the carb, it runs fine, after it looses the prime fuel, it stops. It doe's not go lean or rev up at all. Same thing if I advance the throttle, it just stops. Never ran into this with 2 strokes, but this one is a problem. I was using a Moki remote needle valve, which I bypased, just running in on the carb needle. When using the remote, I opened the carb needle valve 6 turns out, rich, then tried to adjust the remote, then all of this happened, so I just went back to factory settings,bypassing the remote, and it stops after repriming, stalls on high end when advanced.?
I was using an OS/#8, new, then tried a new B&M plug, no difference. Same result.
The back plate it tight, no leaks. I pulled it just to check, very light scorring from the crankshaft, not much. which may be normal , I don know, but to me it should not be touching the backplate at all. I have not pulled the head, no reason too, brand new engine, I still don't understand it..
My concern is, why would the backplate be scored at all, it's 1/8 inch away from the crankshaft. To me there should be no visiable marks on the backplate at all.