Johnson 35hp 3cyl fuel pump problem?

[Davro]

I have a johnson 35hp 3cyl. For some time it has been stopping irregularly and I assumed it was hoses air leaks problem. It has gradually got worse. I have finally had time to replace check tighten everything from fuel tank to fuel rail on carbys. I had placed a clear fuel filter in the line between the fuel pump and the fuel rail when I removed the oil container. I see now that when motor is running fuel filter gradually drains. I can fill it by pumping fuel line. I see from other posts this could mean fuel pump problems. I have two fuel pumps a 438557 and a 438559. The latter being the one that pumps to the fuel rail.

I am thinking that if either of these were working I should be getting more fuel through. I saw on another post that the reason for two was the fuel oil mixer so without that perhaps either one should do better. I understand they are powered by air from the crankcase.

Should I somehow check the air that powers the fuel pumps to see if that is present.

If it is the fuel pumps do I need to get kits for both pumps or can I somehow do without one.

Any suggestions would be appreciated.

 

[Davro]

Re: Johnson 35hp 3cyl fuel pump problem?

I have a johnson 35hp 3cyl. For some time it has been stopping irregularly and I assumed it was hoses air leaks problem. It has gradually got worse. I have finally had time to replace check tighten everything from fuel tank to fuel rail on carbys. I had placed a clear fuel filter in the line between the fuel pump and the fuel rail when I removed the oil container. I see now that when motor is running fuel filter gradually drains. I can fill it by pumping fuel line. I see from other posts this could mean fuel pump problems. I have two fuel pumps a 438557 and a 438559. The latter being the one that pumps to the fuel rail.

I am thinking that if either of these were working I should be getting more fuel through. I saw on another post that the reason for two was the fuel oil mixer so without that perhaps either one should do better. I understand they are powered by air from the crankcase.

Should I somehow check the air that powers the fuel pumps to see if that is present.

If it is the fuel pumps do I need to get kits for both pumps or can I somehow do without one.

Any suggestions would be appreciated.

Further info. Motor is a 1996 model.

I have tried booking it in for attention. As he couldnt get it in for a month discussed matter with mechanic. He stated that little fuel in the filter I described when the motor is at idle doesnt mean anything. He could not believe it would be a fuel pump problem because of the two fuel pumps. Highly unlikely they would both die. He suggested that instead I should run it and see how long it runs for. I ran it for 20 minutes no problems where previously it stopped while idling. (I had assumed there were still problems because of the fuel filter) I am wondering if I fixed it when tightening up fuel lines. I am now going to take it for a run and see how it goes. I assume if there was anything obvious I should do, someone here would have come up with something.

 

[boobie]

Re: Johnson 35hp 3cyl fuel pump problem?

When you are running it, especially at idle the clear fuel filters will look like there is nothing in them but if everything in the fuel system is okay that is normal. When you tightened up all the connections you may have cured your prob. Take it out and run the heck out of it and see what it does.

 

[Davro]

Re: Johnson 35hp 3cyl fuel pump problem?

When you are running it, especially at idle the clear fuel filters will look like there is nothing in them but if everything in the fuel system is okay that is normal. When you tightened up all the connections you may have cured your prob. Take it out and run the heck out of it and see what it does.

Well I took it out yesterday for a decent run. Went well. I think I will spoil it now and change the plugs and give it a bit of a tidy up. I asked what it was worth as a trade in and I might as well keep it as long as it is reliable.

I appreciate the advice.

Thank you

 

[boobie]

Re: Johnson 35hp 3cyl fuel pump problem?

That was a very good mtr. Maintain it well and it should last you a long time.