Hey Demon Sizzler!

I have a 72 340 Thermoquad. It works great in normal driving and under full throttle, but after you open the secondaries and go down to idle it runs rough and rich for a while untill you rev it a few times then back to normal. The secondary shaft has play and I believe the butterflies hang up and is causing these problems. I've had this carb for years and had to unhook the secondaries when I ran it for a while on a 360. It runs good and has nice power on my lightly hopped up 273 but that damn issue is puzzling. All I can come up with is the worn shaft. Can you repair this or do I need a different bottom plate?

I just went through the carb again today. Cleaned, checked float levels, gaskets etc. All looks well.

I have a couple bigger TQuads that have always been excellent carbs on 440's and 360's. I would really like to use this smaller one if I can fix it, or get it fixed.
Author: admin