Gas leak from Carb

[Seanjh338]

Hi guys,

New to boating here just bought my first boat. any way I have a 1975 85 hp johnson 85ESL75
outboard motor and have been having a problem with gas leaking from the carb. I can start it and get it running but when i turn off the motor gas comes pouring out of the carb. I have the motor tilted up when this happens. when tilted down it doesn't is this normal?

 

[flyingscott]

Yes that is normal. I don't remember if that has a reclaim hose under the airbox or it could just be a leaky airbox gasket

 

[Seanjh338]

Well that is good new. other issue i am having is that when i start up and push down on the start up lever the motor then chokes and shuts off. any idea what could be going on with that?

 

[flyingscott]

You need to keep it idling a little high about 1500 rpms until it warms up couple minutes or so. You can't just put the lever down right away.

 

[Seanjh338]

okay sounds good. thank you. I appreciate the help so far. So when cold starting the motor keep it tilted down so motor doesn't leak from the carbs and just run for a little while with the lever up before putting the start up lever down.

 

[flyingscott]

Yup that should do it

 

[emdsapmgr]

Most of these really early crossflows never had power trim. Power tilt was available as an option. So the majority of consumer engines pretty much stayed just level all the time. When the option of power trim became popular, the leaking carbs became more of a nuisance problem-now that the owner had the ability to change the running attitude of the powerhead. Even tilt the engine up out of the water when storing it. Later crossflows (around 79) did not leak as much, and further carb improvement was made in the next few years. The cork gasket around the airbox seems to always leak-so keep a new one handy. Use gasket sealer to permanently attach it to the airbox cover so it does not get distorted if that cover is removed occasionally. replace as needed. All of them use a rubber hose to drain the excekk airbox fuel-oil back into the lower engine when running. Make sure your airbox drain hose is connected and not cracked. None of the factory hoses on these engines will tolerate ethanol fuels, so if you have any original hoses on the engine, they should be changed. If you don't you will wind up with black bits of hose inside the carb bowls and even the jets..a problem.

 

[Seanjh338]

this does not have a power tilt n trim it is tilted manually.

 

[Keyboardman]

I store my '74 50hp in the down position all the time unless towing to the ramp.