'76 15 HP Johnson no fuel through carb?

This old motor runs great one day then refuses to start a week later. It appears no fuel is passing through the carb to the motor. I have tested my fuel system and fuel is being supplied as it should all the way up to the carb, but something is preventing it from actually entering the carb to be mixed. I applied a small amount of air pressure (more pressure than typically supplied by the fuel pump) and could not blow through the carb. Has anyone experienced this type of blockage/clogging? I assume its possibly a piece of debris, but when I pull of the carb where should I be checking? I have a service manual and its been valuable in the past, but isn't providing much insight to this problem! Thanks in advance,<br /><br />Matt Branham

Re: '76 15 HP Johnson no fuel through carb?

Verify compression first before you undertake any other means of repair on this engine.<br /><br />Next remove the hose at the carb...squeeze the bulb and see if gas comes out. If so...the carb will have to come off and be Rebuilt or cleaned. If NO fuel comes out..the problem lies somewhere in the tank or fuel line.<br /><br />TMD

Re: '76 15 HP Johnson no fuel through carb?

Matt....just to add to TMD's advice, while you have the gas line disconnected from the carb, crank the engine and see if the fuel is spurting from the fuel hose. This will verify the fuel pump is working.<br /><br />Also a spark check wouldn't hurt either. This ignition should jump a 7/16inch gap with a hot blue spark.<br /><br />And take a look at the float bowl gasket on the carb. If it's black, which is the older material used for bowl gaskets, then your way overdue for a carb over haul. Could be a bit of this gasket floating around in the bowl.<br /><br />Keep us posted as to what ya' find. We like feed back. Thanks.

Re: '76 15 HP Johnson no fuel through carb?

Thanks for getting back with me so quick. I took the carb and bowl off this weekend, there was some powdery like black residue in the bowl, and the gasket was the black type. When I first removed it I notice the float and needle valve were not free moving, after taking the mechanism off and back on, it was free and the needle was operating smoothly again. I'm waiting on the carb rebuild kit I ordered to finish cleaning the carb and put it back on the motor, but I believe the problem has been solved.