"YS engines are for those with meticulous mechanical skills. Nothing less will do."

Hehe, thanks for the encouraging words Artisan.

locoworks, I thought that was the problem to begin with which is why I went out and bought another brand new plug. No difference.

How does the check valve have anything to do with the carb leaking? I will check it anyway...

"The 63 is a super engine and once dialed in it is very trouble free."

That's why I got it!! I guess all that raw power had something to do with it too...

I'll admit, I've had a couple Saito's and they were also super engines with no trouble. May not have power like a YS, but they ran good!

I will go fiddle with it once more today and if it still get's mad at me I'll send her in.

Thanks again for all the replies.