1996 johnson 48 special fuel pressure

[5string]

I'm having trouble losing fuel pressure. When I pump the bulb it never feels right, stays mushy. I have replaced the fuel lines, connectors,and the pump bulb. I have tried a new tank and just rebuilt the fuel pump. I'm guessing something further up like the carbs are causing the problem. It seems to me that there has to be an air release somewhere in the carbs. If I take the fuel line off at the motor and pump the bulb with no connector, just open hose it pumps fuel through fast. If I leave the conector on it does nothing so with the end of the line open fuel goes through. It's like there is something plugged up somewhere. Anyone had any problems like this. The motor runs, starts right up but it will only run a few minutes then I have to pump the bulb every couple minutes before it starts to sputer then pump it up some more.

Thanks, 5string

 

[R.Johnson]

Re: 1996 johnson 48 special fuel pressure

If you can keep the engine running with the primer bulb, then the fuel pump can't be delivering fuel as it should. All carb's are vented out the top of the bowl, otherwise they would air lock.

 

[rickdb1boat]

Re: 1996 Johnson 48 special fuel pressure

Re: 1996 Johnson 48 special fuel pressure

Make sure the pulse hose from the pump to the crankcase is secure. This would not affect the bulb, but would affect operation of the pump...Try putting the bulb in a vertical position with the arrow facing skyward. See if that helps with pumping it up. The bulb does not stay hard once the motor is running, but it should not go flat..

 

[5string]

Re: 1996 johnson 48 special fuel pressure

The bulb will not pump all the way up, it used to but not now. Before you could feel the gas rushing through when you pumped it but not now. I pumped it with the engine cover off watching closely and I don't here or see and leaks. The only other thing is the carbs, I'm taking them off tonight and gonna check the floats and see if they are gummed up, I don't know what else to do. It acts like it is air locked at the motor end and there is no where for the gas to go. I know gas is getting to the carbs cause it runs. I will let you all know what I find, Thanks for the help.

5string

 

[DJ]

Re: 1996 johnson 48 special fuel pressure

Your engine is old enough to suffer from "gunk" built up in the carbs.

Rebuild them using OMC/Bombardier kits. Pay special attention to any orifices. Carb cleaner and compressed air are your friends.

Make sure, while you are at it, to replace all underhood fuel lines.

Pay special attention to the "pulse" lines that go from the crankcase to the carbs.

 

[R.Johnson]

Re: 1996 johnson 48 special fuel pressure

Take the pulse line off the fuel pump, and pump the bulb. If fuel flow's out that line.

 

[5string]

Re: 1996 johnson 48 special fuel pressure

I had to order the kits online so last night I took the carbs of and checked them, they were clean as a whistle, I mean no gunk or varnish at all. I sprayed every thing with carb cleaner including all the lines and put them back on, the bulb pumped up in 3 pumps, I knew it was right the first pump cause I could feel the gas rushing through. Thanks for all your help, I'm going fishing.

5string