Ocean Pro wants to stall @ trolling spd...

[SteveSC]

2000 Johnson 250 hp ( not a FITCH ). I keep wanting to think it's sucking air somewhere. Runs good from WOT to around 8 mph, any slower it wants to stall. You pump the bulb primer before it stalls and it smooths out for a few minutes then it starts again. ( Note: it'll idle all day in the yard on muffs. ) It was acting this way when I bought the boat\motor last spring.

Everything is new from the tank to the motor: fuel filter - seperator - new fuel lines - primer bulb replaced twice - new fuel pump new fuel rail - new fuel lines on all carbs - fresh ethanol free gas always. Can see no fuel leaks anywhere.

I've got an Atwood glass fuel filter on it - I've noticed some air bubbles in the filter even when it's idling. That can't be right - there should no air in the fuel delivery system. But I'm at the end of ideas from where it's coming from.

Motor fires right up after it stalls - no problem there. Like I said, if you catch it stalling and get to the primer bulb it'll smooth right out ( primer bulb oriented w\arrow up with flow fuel to motor ).

I thought about putting an electric Holley red fuel pump between the primer bulb and motor to have positive fuel pressure all the time toward the motor.

I've been fighting this issue for 9 mons... I've posted this problem before on another site but was reccomended to post it on iboats. Any ideas will help at this point.


2000 Sea Pro 255 CC
250 Johnson Ocean Pro

" Always have a plan. "

 

[Dhadley]

Re: Ocean Pro wants to stall @ trolling spd...

You are describing a fuel delivery issue at low speed. Sounds like the carbs are OK since it will run good if you manually supply fuel. It could be a couple of things but one thing that needs to go is the glass filter. Those motors are pretty sensative to fuel restrictions and it's not recommended to us a glass in-line filter on that motor.

Then you might look at any fittings in the system. Bulkhead fittings are not the greatest idea, filter fittings should all be straight and 3/8", no 90* fittings. Then look at the anti-siphon valave at the tank. It may be starting to stick at low rpm. All fuel line should be 3/8" ID and in good shape internally. No tie wraps pinching the lines, no loose connections etc.

You said you put on a new fuel pump. What kind? Did you change the pulse limiter when the new pump was put on?

 

[SteveSC]

Re: Ocean Pro wants to stall @ trolling spd...

You said you put on a new fuel pump. What kind?

When I bought the boat]\motor las t spring it was a VRO system. Thinking the problem was the VRO fuel pump ( maybe a diaphram or something ) I replaced it with a new OEM non-VRO fuel pump. The problem did not follow the old fuel off the motor - same stalling problem with new fuel pump.

Did you change the pulse limiter when the new pump was put on?

I did not change the pulse limiter. Should I have..? Can you explain what the pulse limiter does..?

Then look at the anti-siphon valave at the tank. It may be starting to stick at low rpm. All fuel line should be 3/8" ID and in good shape internally. No tie wraps pinching the lines, no loose connections etc.

Anti siphon valve....where is it at the tank ? I don't remember seeing anything when I replaced the fuel line @ the tank. I've been told that you can just remove it and be without one....I don't know about that.

Like I said, I've changed all fuel lines from the carbs. back to the tank and everything in between.......the stalling problem hasn't got any better nor any worse. I did use tie wraps on the fuel lines but then I had to cut tie wraps off the fuel lines to replace them. I replaced the fuel lines with the size that came off - 3\8" ---- 5\32" is the size that fits the fuel rail to the carbs.. There's no kinks or 90s in the lines - I was careful with that.

It's like I keep missing the problem all together... You might be on to something with the anti siphon valve. Could either that or the pulse limiter be the problem....?

 

[Dhadley]

Re: Ocean Pro wants to stall @ trolling spd...

The pulse limiter is either screwed into the block or is in-line with the pulse line that operates the fuel pump. A new one should have come with the new pump. If it's partially blocked the pump won't see a strong pulse and will act as a weak pump at low rpm. Squeezing the bulb will basically by-pass the pump.

The anti-siphon valve is nothing more than a ball & spring inside the fitting coming out of the tank. It'll look just like a normal barb fitting screwed into the tank with the hose attached.

 

[w2much]

Re: Ocean Pro wants to stall @ trolling spd...

Does your alarm sound? I seems that it would if you have a restriction. You can easily take out your pulse limiter and clean it with carb cleaner. Worth a try.