Mercury Optimax 150, 2 stroke, 2006

by Ken Todd
(Centennial, Colorado)

220 hours. Fuel injectors and air injectors have been cleaned, tested and 3 of them replaced. New fuel filter. VST tank has been removed and thoroughly inspected and cleaned. Boat gas tank has been drained 100 %. No water in fuel.
Engine hardly idles and if it does it is very rough and dies within 15 - 30 seconds. I can rev it up and it will run, sounds good, maybe not 100 % (sound good) but definitely in the 90 - 95 % range of a perfect smooth running and sounding engine. Been through this scenario multiple times, no change.

My air pressure tests at 79 psi ( perfect).My Fuel Pressure tests at 81 - 82 psi (should be 89 psi). My QUESTION is.... "Is 81 psi "low enough" to cause the above referenced symptoms. I am assuming that I need a new High Pressure fuel pump but wanted to post here before I spent $ 500.00. I, nor anyone else, can figure this motor out. In Denver, ha ha, I think I might open my own engine shop based on the results I have received from a couple of shops.

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