2001 150HP HPDI Loading up with fuel

[twinrelief]

I've got one of two HPDI 150 that started loading up with fuel at end of last year. It is burning 1-1/2 to 2 times more fuel based on the Yamaha fuel meter. Leaving a lot of fuel in the water. I did change all six plugs and found one cylinder with white buildup. It did help, but still burning the same amount of fuel.

Engines have over 1200 hours on each.

Any ideas on what may be causing this? Oxygen Sensor?

Thanks

[boscoe99]

Have the injectors been flow tested?

http://www.brucatofis.com/

[rodbolt17]

have you TESTED the lift pumps?

[Hollywoodfish]

One of my motors did the same a few years ago, it was dumping fuel in the water. It was an issue with a broken diaphragm in one of the mechanical fuel pumps. I replaced both of them and it solved the issue. Was a relatively easy and inexpensive fix.

[twinrelief]

Thanks, I'll have to check it out