aven2rus

Has your source for fuel changed? Take read through this.

http://www.used-boats-canada.ca/item...d-boat-engines

Specifically the Vapor Lock section of the article. I ran into similar issue last year when one of the Marinas I used made the switch to ethanol gas and failed to inform me.

After that I ran the addative, added a second blower and ran blowers full time it never happened again.

S.E of Disorder

No, I fill up at the same station every time and it's ethanol free.

cloudmaster_321

What year/model are your engines?

Griff

They are in the VST tanks. Its a small tank at the rear, top of the engine and there are fuel lines run to it.

S.E of Disorder

It is a 2000 model rebuilt in 06. I don't have the VST.

cloudmaster_321

I don't know how the fuel return is hooked up on your year engine, but esentially the theory is the same for all of them. If the excess gas after the fuel regulator is not returned back the main gas tank, it should. That would greatly reduce fuel temps by constantly circulating fuel vs trying to burn heat soaked fuel.

S.E of Disorder

I don't think it goes back to the tank, it has a one way siphon valve at the tank.

tunertech

sounds like the tank vent maybe restricted since cracking the filter gets you back on your way.

to check for vapor lock pop the schrader valve located on the front of the fuel rail it should be solid fuel. located just under the upper plenum in the center.

test your fuel pressure as well and at the same schrader valve SB between 40-43 PSI static also check it under load. Your FP maybe ready to dump

The regulator may be faulting as well. Remove vaccumn reference line and see if the situation continues.

All fuel bypassesed fuel goes back to the filter with the COOL FUEL system.

Mercruiser made a low pressure boost pump add on as a service kit to supplement the cool fuel system.not always required.

Griff

Then the fix is Mercruiser booster pump kit. It plugs into your current wiring harness and will cure the problem.

S.E of Disorder

Thanks everyone I have looked for this kit but can't find anything about it.