Trouble shooting

[davecc]

Chasing advise
My boat has been playing up for a few trips, thought I fixed it but not to be.
Boat is Allison vison with 150honda 2004 package, After running for a amount of time it starts to surge, bring it down to idle no problem, free rev no problem, put load back on it and no go.
It did it yesterday, So I felt the primer bulb and it was empty & wouldn't pump up< when I undid the water trap bleeder, it had a heap of air come out of it, than it bleed back up.
So far I have reset the valves Plugs all filters & O rings New electric fuel pump Clean the tank & all fuel system. Now im not sure what it is
Any help would be great
Cheers Dave

[marto78]

It sounds like you have a leak in the fuel line before the water trap and it is sucking in air.

[Noelm]

a couple of things come to mind here, first and foremost, make sure your fuel line is not kinked, and your tank air vent is clear, can you run it off a small remote tank with a new hose and primer? Revving in neutral does nothing and tests nothing (well up to a point) you need to remember that the motor fuel pump "sucks" so any restriction or leak between the motor and the fuel tank can cause drama.

[no chicken tonight]

Id replace all hoses from the tank to the seperator including primer bulb and hose clamps. Pretty sure you will nail the problem, but at 10 years old they'ed be due to be replaced anyway.

[Fed]

I undid the water trap bleeder, it had a heap of air come out of it, than it bleed back up.
Are you sure you didn't have a heap of air go into it rather than out?

[davecc]

Are you sure you didn't have a heap of air go into it rather than out?
Fed,, Yes it had a heap of air going into the filter

[Fed]

Then you're pulling a vacuum somewhere before the filter.

Don't waste your time looking for air leaks.

First place I'd check is the vent fitting they can get salt encrusted on the little wire mesh.

[mirage]

Sounds like an old primer bulb collapsing.