Stuck throttle valve

[666cb777]

The throttle valve in my right carb jams. I first thought it was the valve itself but when I switch the two the problem is the same. So the carburetor isn't nice and round anymore.
Anybody knows a good solution? Any tips on using modern carbs? (I'd prefer keeping the old stuff.)

Thanks in advance.

[48lesco]

Hi - That's a pretty common problem. First make sure the mounting nuts aren't too tight. I'd say about a half turn past finger tight is enough; the carb body can distort if they're too tight. If the carbs fall off later, they weren't tight enough. Next, look at the slide and you can usually see where it's rubbing. If not color it with some magic marker and try it again. Find out where it's rubbing and take some 800-grit or so to the bore - not the slide. Clean it out with an oily rag and repeat until it bottoms out smoothly.