johnson 35 hp fuel system problem

[TerryMSU]

Hello:

I have a 1978 Johnson 35HP. Last night it would not start. The prime ball would not get hard nor could I hear it pumping fuel through it. Eventually, I pulled the fuel filter off the fuel pump and pumped the ball. Then I could pump a little gas up to the filter. When I re-installed the filter and pumped til the ball got hard, it started and ran just fine. The two possible issues I can see are either the hand pump will not prime when dry (or check valve in the ball is bad) or possibly the float bowl valve is not working correctly. I strongly suspect the hand prime pump (the "ball") as more likely. Any comments?

Thanks,
Terry

 

[F_R]

Re: johnson 35 hp fuel system problem

Some (most) of the aftermarket prime bulbs are crap. They have lousy or no check valves in them to prevent backflow. At the very least, you have to hold them vertical so the flow direction is pointing up so gravity will operate the check valve.

 

[wbeaton]

Re: johnson 35 hp fuel system problem

Yup. Probably crappy bulb. Also check the quick connects at the tank and motor. Sometimes they don't seal well and you get the same problem.

 

[TerryMSU]

Re: johnson 35 hp fuel system problem

It was the bulb. Replaced the bulb and it works much better. I still have a different starting issue but will open another thread on that.

Thanks,
Terry