Motor cutting out

[Scoot]

My brother was using our boat today and it cut out while on plane, at about half throttle. Apparently it didn't just stop instantly, but bogged down and died over the course of a couple seconds or so. It sounds like a gas issue to us- do the resident experts agree? Suggestions appreciated...

The boat is a 1999 Skeeter and the motor is a 2000 model 150 Yammy HPDI. I've never replaced a fuel filter on it- I'm guessing that's a good place to start. If yes, what's it look like and where is it? I found what looks like a filter on the side opposite of the starter, but I'm not sure it's a fuel filter. Sorry, if I sound like a mechanical dummy it's only because I'm a mechanical dummy.

Again, any info appreciated. Thanks much!

Scott

[Bigtom]

Check all of your fuel lines for cracks also you primer bulbs, I am not too wise on that motor. Do you check your spark plugs often?

Also did you ever get it started back up?

[HANS76]

Sounds like the motor is sucking air somewhere.

[Scoot]

Thanks for the quick replies, fellas. Yes, it started right back up, he took off, it ran fine for a minute, then did it again. This happened three more times.

[HANS76]

He had the air vent open on the tank right?

[boatfixer]

He had the air vent open on the tank right?

Im sure its a built in tank.

I'd look into the fuel filter 1st.

[HANS76]

My bad! just throwing ideas out there.

[boatfixer]

#5 Is the entire filter assy

#11 is the actual element

You should find it on the port side

[boatfixer]

My bad! just throwing ideas out there.

Hey no problem! Very valid suggestion if a portable tank is being used!

[morepower02]

A Hpdi should have a 10 micron spin on filter in the boat. If not it will still have the engine mounted filters. One before the lift pumps. One on the electric fuel pump pickup in the VST and one after the VST before the high pressure pump. Each injector also has it's own screen filter but they are never a issue. The fuel system on a HPDI can be fun to diagnose. I start with a vaccum guage between the tank and the engine. Run at WOT and make sure that vaccum does not increase. If vaccum Is in check then I run a low psi fuel guage after the 2 lift pumps before the VST. If the lift pumps are in check than I tap into the medium pressure pump in the VST. If that pressure is good then I check the high pressure pump. The high pressure pump requires a laptop to read the psi, but the problem is almost always found before the high pressure pump. Let me know if I can be of any help.

[Scoot]

Thanks guys- I appreciate the input! I'll check all the lines for cracks and replace the filter. If that doesn't cut it, I may be bringing it in...

[marine_man]

For clarification sake... Scoot's motor is a 150 OX66 Yamaha.. not a HPDI.

marine_man

[morepower02]

Yep, just noticed the year.

[Scoot]

For clarification sake... Scoot's motor is a 150 OX66 Yamaha.. not a HPDI.

marine_man

LOL- told ya I was a dummy!!! Rob could go into painstaking detail as to just how little I know... Thanks guys and thanks in particular to Rob for all of his help- that dude is one knowledgable and helpful fella, for sure!

[boatfixer]

For clarification sake... Scoot's motor is a 150 OX66 Yamaha.. not a HPDI.

marine_man

Kinda what I thought

[Scoot]

FYI- I tried the suggestions I figured I could handle and didn't come up with any improvement, so I brought it in. Turns out the fuel pump diaphrams were shot and that was (hopefully) the problem. I haven't had a chance to run it yet, but the guy who worked on it was positive that was the issue. I hope he's right!

Thanks again for the suggestions and help.