Johnson 150 v6 carbs

[rich_benson]

I used sierra carburetor rebuild kits for all six carbs. One of them is still leaking out of the bowl gasket, and where the carb mounts to the back plate (another gasket). Can I use gasket maker on the outside of the cab where it seems to be taking air in and leaking some gas?

 

[saltchuckmatt]

I used sierra carburetor rebuild kits for all six carbs. One of them is still leaking out of the bowl gasket, and where the carb mounts to the back plate (another gasket). Can I use gasket maker on the outside of the cab where it seems to be taking air in and leaking some gas?

If it ain't right, take it back off and see why. I've never used gasket maker on a carb and possibly you have warped the back??? Not sure I'm qualified enough on this one.

 

[Chris1956]

Gasoline will dissolve most gasket maker material. Fuel is supposed to travel from the throttle bodies, to the carb bowls. A part of the gasket seals that passage.

Sierra has been known (to me anyway) for providing the wrong gaskets in the carb rebuild kits. You might compare the gaskets to the originals.

On those spaghetti gaskets, it can help to wiggle the carbs on the throttle bodies to seat the gasket in the groove, and then install the bolts. A drop of silicone can hold them in place as well.

 

[flyingscott]

Which 150 do you have? I am going to guess it's a looper. Check for warped float bowls especially if they are plastic. Check the mounting surface of the carb for being warped.

 

[rich_benson]

Which 150 do you have? I am going to guess it's a looper. Check for warped float bowls especially if they are plastic. Check the mounting surface of the carb for being warped.

Yes it is a looper - used automotive gasket maker (fuel resistant) for now until I can get a newer engine. This one is starting to alarm after 4k RPMs now. Still determining if gas restriction or overheat. It does allow me to turn it off and right back on without alarm at 4k RPM. Starts as beeping, then solid tone alarm.