Dave,
here is a thread we talked about this motor before.

/www.rcuniverse.com/showthread.php?s=&threadid=83520

I am still having mid range problems. I opened up the regulator screw like you said, and it didn't help. I went 1/4 turn at a time. I went out until the regullator screw was fixing to come out. and nothing fixed my problem. I then started back where I was before, and i start screwing it in 1/4 turn at a time, and it would not work. So i am at a loss.

Ever since Ys work on my motor in August, because of a bad regulator spring. ys raplaced my regulator spring, and piston. I have had nothing but problems out of this motor. Now since it out of warranty. It looks like I am going to have to send it in again, to get it fixed.

Can you tell me what I can do, to fix this problem. Because I have a motor that is suppose to be the best 4 stroke made, and it runs like garbage.

Thanks in advance.