Carb issue.-0-320

rv9aviator · #1 09-19-2011, 07:53 PM

After shutting off the engine today I noticed some drips on the wheel pant. It was gasoline and appears to be leaking either from the gasket between the top casting and the main body of the carb or the mixture arm shaft on the back of the carb. Wouldn't the float have to be set too high for gas to leak around the gasket? The engine was running fine and not loading up. When shutting down, the engine doesn't gain any RPM with the mixture is pulled. It just dies.

ABRV4 · #2 09-20-2011, 08:39 AM

I'm going off of memory here but I think that if the valve seat does not seal against the carb body then fuel can leak past a closed float valve and leak out. The float can be at the proper height but fuel can still get by it and flood the bowl. I had to open mine up some time ago and tighten that seat down when I found fuel dripping out. The leaking stopped after that.
Alan
RV-4

rv9aviator · #3 09-20-2011, 09:17 AM

Thanks for the tip. I'll check it out. I have the carb on the bench now.

DaAV8R · #4 09-20-2011, 10:12 AM

In my experience the little Continental carbs seemed to have much more tendency to drip after shutdown if running auto fuel. I?m not sure why.

They seemed to drip at the throttle shaft or out of the bottom of the carb after shutdown (especially if running auto fuel). I?ve had several carbs overhauled over the years because of this problem. I?m not sure any of them really needed the overhaul.

rv9aviator · #5 09-20-2011, 10:31 AM

That's interesting. I am running a mix of avgas and autofuel. Something else to check. I took the top off the carb and checked the float and needle and seat. The only thing I found was the screws that hold the top casting to the bowl weren't very snug. I guess the gasket compressed and the screws lost some of their tension. Going back together this afternoon to see if anything changed.