'98 70HP Johnson losing prime.....(fuel delivery system)

[country_bumpkin]

I'm having a hard time keeping the motor primed. When I do get it started and fuel flows it runs like a top. When I stop the motor for more than a few minutes I have to pump the bulb try to start, then pump again....after a few iterations it will start and run fine

When I pump the bulb to prime the system it doesn't get hard. I bought a smaller 6 gallon tank and new line and it seems to work a little better but it still loses the prime.

Thanks!

 

[kenmyfam]

Re: '98 70HP Johnson losing prime.....(fuel delivery system)

Could be a bad check valve. Position the bulb vertically and make sure the arrow is in the correct direction.

 

[tashasdaddy]

Re: '98 70HP Johnson losing prime.....(fuel delivery system)

if aftermarket hose and bulb, arrow points to motor, also the pump better if arrow is pointed to the sky. but loosing you prime, is either an air leak, or carb needles not closing all the way, or as said check valve in bulb.

 

[country_bumpkin]

Re: '98 70HP Johnson losing prime.....(fuel delivery system)

Could be a bad check valve. Position the bulb vertically and make sure the arrow is in the correct direction.

The arrow is pointing to the motor, but the check valve idea sounds like a winner. I just needed a starting point. I've looked this up in the service manual and the check valve keeps the fuel from flowing backwards toward the tank.....

Is this an easy swap out? I see where it is in the picture but haven't pulled the lid off the motor yet to locate it.

Thanks!

CB