accelarator pump leak
 

I have a Marvel carb on an o-320 and at anual I noticed a small leak at the accelarator pump. What is the cause and solution. It only has 150 hrs on it.

Pete DeCraene

Can't guarentee, but probably just an o-ring around the shaft. Unless it's leaking a lot I'd just leave it be and keep and eye on it.

Leak
 

The accelerator pump circuit had two check balls, one or both may be leaking or there is some debris present. The plungers may also be worn or distorted.
T88

There is a leather packing sealing the pump shaft. It is likely dried out or damaged in some way if the leak is at the shaft wher it comes out fo the carb. It requires carb disassembly and special tools to replace the packing.
Good Luck,
Mahlon
"The opinions and information provided in this and all of my posts are hopefully helpful to you. Please use the information provided responsibly and at you own risk."