2002 Johnson 150 hp J150PXSNF top end skipping

[dorkhead]

Hey Have a 150 here that starts fine runs fine but at approx 3700 rpm to WOT it fluctuates the rpms. Now when you go back and have someone pump the bulb while moving it will catch up and run fine until a second or two after you stop pumping. We checked the fuel lines OK checked for a ball check valve at the tank none there. Do you think it sounds like the fuel pump or do you have any other ideas. Dealers have had it and can't seem to fix it so we are looking for answers ourselves. (me and my buddy) it's his boat .Thanks Mondoo

 

[dorkhead]

Re: 2002 Johnson 150 hp J150PXSNF top end skipping

Also this is not a MISS like an electrical miss because when you pump the bulb it runs like a race seahorse. Like fuel starvation . I think this has an electric fuel pump. Is that right and I don't know how they operate. Is a sending unit not telling it to speed up to catch up with the increase in rpm and throttle position? All help will be much appreciated. Thanks Boats

 

[B.autry4711A]

Re: 2002 Johnson 150 hp J150PXSNF top end skipping

Sounds to me your fuel pump is bad/weak if you have to manually squeeze the bulb to get it to go faster. Someone with more experience will ping in and let you know for sure.

 

[jay gravely]

Re: 2002 Johnson 150 hp J150PXSNF top end skipping

I think Big Bubba is right.By you sqeezing the bulb you become the fuel pump.

 

[R.Johnson]

Re: 2002 Johnson 150 hp J150PXSNF top end skipping

Do you have a pressure, vacuam guage as outlined in the service manual? That woud tell you alot.

 

[dorkhead]

Re: 2002 Johnson 150 hp J150PXSNF top end skipping

No but I'll get one and look into this further thanks all