Fuel Issues

[starkyb]

I have a 1972 mercury 9.8 that will only run for any amount of time when I continually pump the primer bulb. I just replaced the diafraghm, the primer bulb is new, the hose from the tank to the the motor is new and I just replaced the air line from the crankcase to the fuel pump. After it runs for about 30-45 seconds, revs up just before cutting off, the primer bulb is not firm. could there be a problem with my gas can or does it sound like the motor itself. Please help, this is extremely frustrating.

 

[SpinnerBait_Nut]

Re: Fuel Issues

Wrong forum, you need the Merc/Mariner repair forum where I will move it now.

 

[finlay]

Re: Fuel Issues

I would pull the carbie of and clean it, check need and seat and also find the float level spec and check it also.

 

[tashasdaddy]

Re: Fuel Issues

is the vent open on the gas can. having to pump the bulb sounds like a fuel pump problem.

 

[starkyb]

Re: Fuel Issues

Yes, the vent is open. Someone suggested that there may be a hole in the line inside of the can. If my carb needed to be cleaned would it still run well if I pump the primer manually because it does?

 

[hkeiner]

Re: Fuel Issues

I suggest hooking up a another remote fuel tank (say 3 gallon) to the motor to see if the problem persists. If the problem goes away, the problem resides with your existing fuel tank and fuel lines. If not, then it resides with the motor itself. After you know whether it is the fuel supply or the motor, you have narrowed down what needs to be fixed.​

 

[starkyb]

Re: Fuel Issues

I have eliminatied any problems that would exsist with the can but while running it I sprayed starter fluid on the sides of the crank case. It bogged it down letting me know that there is a hole somewhere in the seal. Just seems to be one side of the case. Spraying under the flywheel had no effect. This motor is old so I dont want to put the money into tearing it down. If I were to cover the seal with JB-Weld would that stop the pressure loss and could running seafoam through the motor do any damage to any internal parts. The gas I have been running has none in it but I ran it through last year and once this year.