1996 70 HP Johnson float stuck

[bruce728]

I have a 1996 Johnson 70 hp. I recently rebuilt the carbs. Everything worked great until the second time I went out the float in the top card got stuck causing it to overflow. I thought i fixed it, but after several more outings it stuck again. Can anyone explain why it is sticking and how i can fix it?

thanks to all.

 

[boobie]

Re: 1996 70 HP Johnson float stuck

You could have some junk in the fuel system getting under the needle and seat causing it to flood.

 

[bruce728]

Re: 1996 70 HP Johnson float stuck

Do you think that is something that could happen repeatedly? This has happended 2- or 3 times, and I do have a filter on the system.

 

[phillnjack2]

Re: 1996 70 HP Johnson float stuck

yes it can happen a lot.
there could be a break up of the small hoses from fuel filter to the carbs and also slimey sludge shifting and getting stuck in the needle valve.
Now are you 100% sure you have the float the right way up ?
also is the rubber tip on the very bottom of the needle valve distorted or breaking up and catch a lip etc ?
strange its just the top carb, but I would be looking at the small piped that go from the plastic manifold to the top carb !!!!!
if there is some floating crud in the plastic manifold it would go straight to the top carb and then give you the symptoms all over again.

might be time to renew those those 3 skinny pipes, especially if you have been running on old juice or stuff with ethanol in it ?????


just a few thoughts

phill

 

[bruce728]

Re: 1996 70 HP Johnson float stuck

I am not absolutely positive that i have the float sitting correctly, but I will look at that. The fuel hose from filter to cabs makes sense. I just replaced the gas line from the tank to the engine, and I have no doubt that the rest of the hoses are breaking up from ethanol. They are pretty old. You said, "I would be looking at the small piped that go from the plastic manifold to the top carb !!!!!
if there is some floating crud in the plastic manifold it would go straight to the top carb and then give you the symptoms all over again." I have a manuel, but I am not sure what you mean by the small piped that go from plastic manifold to the top of the carb. Is it related to the hoses coming out of the gas filter? I will look at the diagram again.

But, again, I think it is the old hoses breaking up.

 

[phillnjack2]

Re: 1996 70 HP Johnson float stuck

ok from each carb there is a fuel pipe, trace these back towards the fuel pump.
they all meet in a plastic fitting that looks like a tube with 4 pipes coming out of it, 3 for the carbs and one inlet from fuel pump.
this is called a manifold (its what omc / brp call it ), this is made of plastic and can collect crap or dirt inside it.
Be carefull with this as it can be a bit brittle when old.
Now if this has dirt in there it could float to top and block off the top carb and cause all sorts of trouble.
the fuel pipes from this to the carbs is often over looked when people change fuel pipes, everyone changes the tank to engine pipes, but
they forget about the smaller hoses that will have perished even before the bigger ones !!!!!!!!!

it could be a varnish type build up in the pipes or manifold as well, best to get it off and clean it up to be sure.

its in a right crappy place as well, in between starter motor and plastic airbox, sort of wedged in ha ha .

Here below is a pic of where it is next to the starter motor ..........


phill

 

[bruce728]

Re: 1996 70 HP Johnson float stuck

ok, thanks. I do believe that is the problem. Everything you say makes sense.
thanks again, you all always come thru for me.