Help and tips with my 2stroke outboard please!

[tiago blanquet]

Hi all.

I here in search for help for my 20Hp 20CM 2stroke outboard. The engine is a bit old but have always been properly mantained and had never failed until last time i went in the water.

It failed to start. After that i tried to figure out the problem and noticed that a small hole on the top of the carburetor was pouring gas as the engine run and then stalled. I´ve removed the fuel hose conecting to the fuel tank and then noticed the fuel stoped pouring from that hole and the engine start working ok.

Then with the engine runing i re-attach the fuel hose and noticed the fuel filter filling again quickly until the carburetor start pouring again the fuel from that small hole witch i recon is some sort of overflowing exit.

So the engine runs ok without the fuel tank conected, at least until the fuel on the fuel filter runs out. If i re-attach que fuel hose again the filter bowl quickly fills and fuel start pouring on top of the carburetor.

I think this must be because of building up pressure in the fuel tank caused by volatile gases of the fuel wich pushes the fuel trough the hose and overfilling the carburetor??

Any tips? Tomorrow will test again better in the water with the top of the fuel tank fully open to discard the pressure issue.

Thanks and good day.

[robert graham]

Your float needle valve is stuck or has failed or your carb float may have a hole in it, not shutting off fuel flow after float chamber is filled to proper level. Maybe remove top from that carb to check problem. It works like the float in the water closet on a toilet, just to give you an idea. Good Luck!