1988 Johnson 25 hp will not keep running unless I squeeze the ball

[fishon71]

My 25 hp Johnson runs for a minute and dies - if I keep squeezing the ball it will run. I rebuilt the carb and fuel pump and nothing changed. I ran it for a minute letting the gas go into a jar and had pretty good flow (not impressive) out of the pump but if I don't keep squeezing the ball the carb bowl goes dry - any ideas?

 

[ultra353]

Re: 1988 Johnson 25 hp will not keep running unless I squeeze the ball

Sounds like you have an air leak somewhere. Check all your hoses and connections for tightness.

 

[boobie]

Re: 1988 Johnson 25 hp will not keep running unless I squeeze the ball

If you pull the plug on the carb bowl drain and pump the primer bulb, will the fuel flow freely out of the carb??

 

[hidef]

Re: 1988 Johnson 25 hp will not keep running unless I squeeze the ball

I would check for leaks, make sure you primer bulb is good and the check valves are functioning and make sure your tank is venting correctly. Other than that did you rebuild the pump correctly?

 

[fishon71]

Re: 1988 Johnson 25 hp will not keep running unless I squeeze the ball

If you pull the plug on the carb bowl drain and pump the primer bulb, will the fuel flow freely out of the carb??

Yes, I tried that and gas poured out of the bottom of the carb

 

[fishon71]

Re: 1988 Johnson 25 hp will not keep running unless I squeeze the ball

I would check for leaks, make sure you primer bulb is good and the check valves are functioning and make sure your tank is venting correctly. Other than that did you rebuild the pump correctly?

I took it apart and double check, as far as I can tell it is correct

 

[fishon71]

Re: 1988 Johnson 25 hp will not keep running unless I squeeze the ball

When you say leaks, there are no gas leaks do you mean air or vacuum leaks, all seems okay. Tank and hose work fine on other motors.

 

[boobie]

Re: 1988 Johnson 25 hp will not keep running unless I squeeze the ball

Dumb question again. What's the compression like on the cyl the fuel pump runs off of ??

 

[kenmyfam]

Re: 1988 Johnson 25 hp will not keep running unless I squeeze the ball

Did you check the output of the fuel pump ????

 

[fishon71]

Re: 1988 Johnson 25 hp will not keep running unless I squeeze the ball

Dumb question again. What's the compression like on the cyl the fuel pump runs off of ??

Both cylinders are 125 psi

 

[fishon71]

Re: 1988 Johnson 25 hp will not keep running unless I squeeze the ball

Did you check the output of the fuel pump ????

Yes, cranked over and let run into a jar, flowed good.

 

[hidef]

Re: 1988 Johnson 25 hp will not keep running unless I squeeze the ball

Does the hose from the fuel pump to the carb have a kink in it? It doesn't take much to restrict the fuel flow.

 

[fishon71]

Re: 1988 Johnson 25 hp will not keep running unless I squeeze the ball

Does the hose from the fuel pump to the carb have a kink in it? It doesn't take much to restrict the fuel flow.

no kinks seen

 

[AlTn]

Re: 1988 Johnson 25 hp will not keep running unless I squeeze the ball

looks to me it may be 1 of 2 things..1.the f/p doesn't produce enough pressure to lift the needle off the seat..2. the needle is sticking in the seat

 

[hidef]

Re: 1988 Johnson 25 hp will not keep running unless I squeeze the ball

When you rebuilt the carb did you use the little wire spring that connects the needle valve to the float?

The kink in the line would be right under the carb if you replaced the fuel hose with one slightly longer than stock. I accidentally kinked one when I replaced the fuel lines on 77 25 Hp and it drove me nuts until I figured it out. It would idle but wouldn't run at speed unless the primer bulb was pumped by hand. I removed the kink and it was fine.

 

[fishon71]

Re: 1988 Johnson 25 hp will not keep running unless I squeeze the ball

I took it apart and double check, as far as I can tell it is correct

In the rebuild kit they don't give you everything. What if one of those metal flappers could be bad or a week spring, they do not give you these items. Really seems as the pump is not working, maybe should have bought a new pump instead of a kit.

 

[hidef]

Re: 1988 Johnson 25 hp will not keep running unless I squeeze the ball

Three are only three possibilities we are dealing with I believe. You said you have good fuel flow when cranking the engine over so I think your pump is fine. Next possibility fuel line between carb and fuel pump if that is good and there are no kinks in it that leaves the needle valve and float. If the needle valve is sticking that will cause you grief. The fuel pump can't generate enough pressure but when you use the primer bulb you do over come the sticking needle valve. Did you install the spring clip that attaches the needle valve to the float?

Look at item #21 part # 396521 ? FLOAT VALVE & SEAT ASSY

http://www.marineengine.com/parts/j...ECCM&manufacturer=Evinrude&section=Carburetor

 

[Valley Boater]

Re: 1988 Johnson 25 hp will not keep running unless I squeeze the ball

I had a similar problem and took the motor to the local OMC repair shop and it was only the fuel tank hose closing under feed pressure. It was a fairly old fuel line. Added a new hose and it ran like new.

 

[Kelli]

Re: 1988 Johnson 25 hp will not keep running unless I squeeze the ball

Just fixed the exact same problem. It was the tank itself. Had a crack in the tube that comes up to the fuel line inside the tank. Took a lot of work, new fuel pump, etc.... and poof. Could have had it fixed with a .50 piece of fuel line. Hope you find an easy fix.

I had a similar problem and took the motor to the local OMC repair shop and it was only the fuel tank hose closing under feed pressure. It was a fairly old fuel line. Added a new hose and it ran like new.

 

[AlTn]

Re: 1988 Johnson 25 hp will not keep running unless I squeeze the ball

"tank and hose work fine on other motors"