2001 Yamaha 150 HPDI falls on its face

[ermess]

guys,
I have a 01 150 HPDI that will fall on it's face when I give it the throttle out of the water with no load. checked water seperator filter, checked filter on motor, checked filter in VST, still wants to fall on its face. Any ideas?

Thanks
Ed

 

[jgso]

Re: 2001 Yamaha 150 HPDI falls on its face

is fuel bulb pumped up tight?

 

[ermess]

Re: 2001 Yamaha 150 HPDI falls on its face

replaced bulb, replaced water seperator assy and filter, ran on remote tank as well (isolated boat and motor)?

Thanks
Ed

 

[dstjohn]

Re: 2001 Yamaha 150 HPDI falls on its face

I have a 2002 VMax 150 that had similar performance problems several times. Low power, very sluggish, poor acceleration & would not develop hi RPM. My local Yamaha guy dis-assembled the carbs (all 3) and cleaned / overhauled them. It was pricey ($700 about 3 years ago). After that the thing was like a rocket. I told him if I never knew it was supposed to run that good.

A year later I had the same problem and had to repeat the cleaning. At that time I installed a cartridge water separator/filter and EVERY time i put it away I disconnect the fuel line & run it out of gas. That prevents any furel residue in the carbs from gumming up or leaving deposits when it sits. Three years later and it still runs very well even after 6 - 8 months storage in the desert.

 

[99yam40]

Re: 2001 Yamaha 150 HPDI falls on its face

Running them out of gas never gets all the fuel out of the bowls, lines, and pumps. there are drains that you can use to drain just about all the fuel out of the carb bowls, but I prefer to leave full of stabilized fuel and run often to keep fuel from drying out and plugging things up

 

[ermess]

Re: 2001 Yamaha 150 HPDI falls on its face

Guys,
this is a HPDI (high pressure direct injection motor - no carbs)

Thanks
Ed

 

[rodbolt]

Re: 2001 Yamaha 150 HPDI falls on its face

to start with, DO NOT throttle up an HPDI with no load. they can runaway rather rapidly.
thats why in nuetral it shuts down 2 cylinders and in nuetral above about 1500 it shuts down 2 more.
what is the high pressure fuel rail showing along with the low pressure rail when its failing.

 

[jgso]

Re: 2001 Yamaha 150 HPDI falls on its face

I'm working on same problem. Right now I'm thinking the tank vent is not working properly. Pulls a slight vacuum I'm thinking.