1997 150hp EFI Engine cuts out/dies after running for a while

I have a1997 Mercury 150 EFI that started cutting out after it has been running for some amout of time. The amount of time varies. Some days it does it a lot other days not so many. If it's idling haed headway speed to just above and it's starts to fade I can cut the thottle bad and sometimes get ti so run without dying. Other times I go to take off and the things just flat out dies. It will start right up every time and run fine and at full speed and power. I replace the primer bulb after finding it soft a few times with a attwood brand and the next outing the engine seemed to run great. I went out the second time a the engine started doing the same again. I thought maybe it was due to the cheap primer bulb but I'm thinking it's not now. It there an easy way to test for air leaks ?

Re: 1997 150 EFI Engine cuts out/dies after running for a while

Try a portable tank that you know is "fine". That will either rule out or point to a problem (outside) the engine.

If the portable makes no difference, then filters and fuel pumps would be the leading contenders or even a pressure regulator on the way out.

I would start by changing any (inline) fuel filters (OEM or add on's) including the strainer in the VST.

The electric pump, regulator and fuel rail pressure is best tested at a shop. You do need some specialized tools and it can be somewhat dangerous for those not familiar with the process.

Hello I am having a simular problem with my 94 150 efi mag 2 stroke. I have found that I can get it up on plane by flooring the gas with out it dying . Not sure what that means but I have changed the stator electric fuel pump ,rebuilt the pick up pump, changed the plugs, main fuel line and bulb. All per machanics. I did check the bleed system check valve and found I could blow through both directions ?? Would this be it ? No one up here sems to know nor wish to work on it. Any sugestions? Thank for any time

i just recently had same problem with my 90h mercury. worked fine with aportable tank. Turns out the screen on the pickup in the gas tank was getting clogged. Couldn"t get the tank out so i just removed the screen and put a inline fuel filter.

thanks i did run mine with a portable tank as well but it still does the same thing. very perplexing . i talked to a CDI tech yesterday and he helped me run through some trouble shooting test on the trigger, stator and switch boxes. all tested ok. so he sugested another type of plug. He told me to try them. i guess they burn hotter and if that does not solve the problem he suggested also raising the timeing up by 3 deg. on idle and wot. any other suggestings are welcome. ill keep you all posted. thanks for the time.