fuel leak problem mid 70's Johnson

[bsbladine]

Hey guys, I have a mid 70's johnson 20 hp that runs great but when I shut down the motor it leaks alot of gas out of the, I think, crankcase breather hose. This motor runs so good and starts right up after sitting, but I have got to figure out the fuel leak because my 4.3l boat motor gets better gas mileage. Any ideas?

 

[Rscardina]

Re: fuel leak problem mid 70's Johnson

have you checked your carbs yet?..are they spilling like crazy?

the pulse line you speak of is what runs the fuel pump..is it cming in that way?? try starting it and let it run to warm up. then shut her downa dnsee if the fuel is coming from the crankcase or from the pump hose..could have a pump that leaks by i guess..

i'm not 100% on this but fuel in the crankcase doesnt sound good.....

 

[bsbladine]

Re: fuel leak problem mid 70's Johnson

Well, I just ran it in nuetral since I only have a small bucket for water, but I did not have any gas leaking from anywhere. It has me confused because it has been doing it to me for about the last 8 outings. The only difference is this time I decided to bring the boat home to work on it instead of leaving it at the cabin. Could I have a sticky float in my carb that bounced loose after traveling? Or is there some reason it would only do it while in gear? Any ideas would be great. Thanks

 

[Rscardina]

Re: fuel leak problem mid 70's Johnson

a sticky float will do that.. if it cant seal off, fuel will spill.. if the fuel keeps coming then it will fill that space..but the fuel tank has to be above the motor for that...and I assume you dont drive around holding the tank in the air..so forget that theory.

the odd thing is too much fuel will bog and choke you...so its really weird. this is why i mentioned fuel pump. since the engine cranks make the pump pump..i thought perhaps some fuel coming out that pulse line and filling it....

did you run it and then pull the pulse line off??...can you see the carbs to know its not spilling at all.?.

 

[bsbladine]

Re: fuel leak problem mid 70's Johnson

I ran it but am unsure what the pulse line is. The gas was coming from a hose that connects right to the bottom or crank area of the motor and then runs to the back of the housing where it isn't hooked up to anything.