'76 Johnson 25 hp fuel problem?

[barrynfla]

Was out in Tampa Bay today and the motor was running well. Stopped to fish a few times. Started back to the ramp when the motor coughed and stalled. The ball was soft and the inline fuel filter was almost empty. Pumped the ball back up (took a bit of pumping) and the motor pull started very easily. Ran for a short time and coughed again but I pumped the ball quickly and it didn't stall. All was well after that. Model #25R76E.

It's been running okay lately, the carb was rebuild recently, gas was fresh, tank vent was open. This motor has great compression (120/120) so I want to catch any small problems before they become big problems.

Not sure what happened. Bit of water in gas? Any ideas, guys?

Thanks!

Barry

 

[kodibass]

Re: '76 Johnson 25 hp fuel problem?

raise tank higher than carb intake, prime start and see if it will stay running with this gravity feed set up, if so wait a bit then lower the tank and see if it dies, also you should remove fuel hose from pump to carb intake pull motor over 5/6 pulls briskly and see if fuel pulses out. let us know.

 

[barrynfla]

Re: '76 Johnson 25 hp fuel problem?

I'll try these, Kodibass. Thanks.

Just looked at the hose connection from the fuel pump outlet to the bottom of the carb. It's like a small zip tie around it. That should be fun to remove! lol

Seriously....have you removed that hose before? Is there a way to do it without cutting into the hose?

I was just wondering if I picked up a bit of dirt from the tank which caused the stalling then worked its way out.

 

[bonzoscott]

Re: '76 Johnson 25 hp fuel problem?

Just remove the end of the fuel line at the pump, coming from the carb if you can't get at it easily on the carb. Crank motor and watch for good fuel pulses out of the pump.

 

[barrynfla]

Re: '76 Johnson 25 hp fuel problem?

Finally got to try to see what the problem is. I started the motor on muffs and it ran well for a short time when, I assume, the carb ran out of gas. The bulb was soft and the inline fuel filter was empty. Pumped it up again and it started and ran but in a few minutes the same thing happened. I took the fuel line from the pump to the carb off at the pump end, disconnected the spark plug wires and pulled the rope a bunch of times. I did NOT see any fuel being pushed out of the pump at all. I blew into the hose and can tell that there is no blockage in it. Is this a clear indication that I need to replace the fuel pump? Is this easy to do? I'm not real mechanically inclined.

Thanks, y'all.

Edit: Very high prices for a complete fuel pump. Will a fuel pump repair kit do the job? Are they even available? The part number on the pump is 312631.

Edit again: Pulled pump off motor. Squeezed primer bulb and fuel squirted strongly out the fitting to the carb. No fuel came out the hole that leads to the crankshaft which leads me to believe the diaphragm is okay. I'm getting more and more confused!

 

[barrynfla]

Re: '76 Johnson 25 hp fuel problem?

I really want to get out on the water but need to do the right thing about the fuel pump. Any suggestions, guys?

 

[Xcusme]

Re: '76 Johnson 25 hp fuel problem?

Sounds to me that the diaphragm IS broken. Either get a kit to rebuild the fuel pump or get a new fuel pump and install. Fuel should NOT come from the port that connects to the motor......only from the port that goes to the carb.

 

[barrynfla]

Re: '76 Johnson 25 hp fuel problem?

Sounds to me that the diaphragm IS broken. Either get a kit to rebuild the fuel pump or get a new fuel pump and install. Fuel should NOT come from the port that connects to the motor......only from the port that goes to the carb.

Fuel didn't come from the port that connects to the motor.......just from the port that goes to the carb. I probably worded my last post all wrong. Anyway, I ordered a new fuel pump as there is no rebuild kit available for this pump. I hope this fixes the problem!