Chainsaw Repair

Hello everyone I have a Husky 394 and I just rebuilt the carb with a new kit. The carb is flooding from the pressure of the fuel tank. The inlet needle has been adjusted but this carb is still flooding real bad the fuel fills up the air filter flange and cylinder. Any suggestions?

You can check if the metering valve holds with the carb off the engine by putting a little pressure on the fuel inlet of the carb.

The metering valve should hold back close to 15 psi pressure or more.

It should re-seat after opening by down to 10 psi pressure

This is called the pop - off  pressure check.

The fuel pump side of the carb can make somewhere close to 7-8 psi fuel pressure and the metering valve has to be able to hold back this pressure if there is no vacuum through the carb.

The actual function of the metering valve is to act as a demand regulator for fuel delivery for the engine. It is to remain closed unless there is a vacuum signal from the engine that it is running. This vacuum signal can be developed by pure intake vacuum when you choke the engine or it can be developed by venturi vacuum when the engine is spinning faster.

It is supposed to take a about 4" wc vacuum on the underside of the diaphragm to open the valve but there is not a simple to apply this or check the actual vacuum as it to do the pop - off pressure on the fuel inlet of the carb.

Run it with the cap **** open a bit.  If that fixes it, tank vent it is.