Sea doo with mercury 240 engine starts and idles fine but wont take throttle

[Tomlibby40]

trying to help a friend get his boat running right that he purchased online from florida and hauled back to maine.It ran great for the first couple rides out then started gurgling and sputtering.It will start right up and idle fine,smokes alot,but when you try to give it throttle it gurgles ,sputters and gags.when you shut it off it sits there for awhile with smoke coming out of throttle body area.I have replaced all plugs and have great fire.He had someone check compression and was 125psi and fuel pressure was 60 psi.I am a 30 yr mechanic but not much experiance with boat motors.Just trying to help him out as i think he got screwed on the purchase.It seems like to me its getting to much fuel,pulled the fuel pressure regulator and the bottom oring was gone so i replaced it with on from the hardware store and made no difference.looks like someone has been beating on it.It allmost acts like water in the gas or something.Suggestions would be greatly appreciated.I was told these merc engines really fly when you get them running right.Its been tied to his dock unusable for 3 months now.

 

[rsatina2002]

Please let us know what kind of engine you've got? was it a Mercury M2 240 Gen 1 or Gen 2 engine, provide pictures so we can help you out. Fuel pressure supposedly 36 PSI not more than that, that might be your problem there...

 

[Tomlibby40]

Im not sure wich generation it is and thought i had taken pics of motor but cant locate them.Will have to get my buddy to take acouple.I do know its fuel injected model.all coils are on backside and has a shit ton of sensors on it.maybe the fuel pressure regulator is bad from people beating on it.Couldnt match it up at auto parts store.Sure looked like a typical fuel pressure regulator thats used in autos but couldnt cross reference cause numbers were really faded.How do you tell what gen the motor is?

 

[Tim75]

Assuming you do not have the opti-max engine-

Is the flywheel cover round or square-ish? Is there a car-style alternator on the engine?
Round cover=gen 1.
Square cover=gen 2.

I went thru the same search at Rock Auto. Lots of regulators, no specs on them and look similar, but not quite right. I had fuel pressure of about 65 psi. Installed after-market adjustable fuel pressure regulator.

125 psi compresion is a bit low, but if uniform, should be OK. Was the compression checked at WOT?

 

[Tomlibby40]

Its definetly a merc,i want to say a square cover,car type alternator on right side if in boat faceing back. It has the high pressure pump on front and low pressure on the right side. Is 65 psi what you had before installing a aftermarket?