Have a relatively new Tower .75. Runs well at idle, and have the top end set 300 rpm below peak. Problem is, after running a few minutes at mid throttle, when I go to full throttle, it consistently stumbles.

Any ideas?

Thanks,
Frank

The best place to start is to lean out your low speed needle valve and see if it improves. It sounds too rich right now.

I did try to lean the low speed needle, but then it dies at idle.

Thanks,
Frank

I had the same trouble with one of my Tower .75s, very rich in the mid range with poor acceleration. The second Tower worked fine. I got a replacement carb from Tower Services. The replacement carb works great.

While I was waiting for the carb, I substituted the carb from an SK 90. It worked perfectly.

Ed, thanks so much. Have heard the same from more than one source.