2005 yamaha hpdi problem

[Capt Harv]

I have twin 2005 HPDI 200 HP engines. Both engines have started stuttering momentarily when I come over a wave. Never both at one time, but each does it sometime. It last about a second then engines come up to full rpm. Runs perfect on flat seas. Change water separators and found a couple teaspoons of water in each and very little debris. Problem persists. Anybody have thoughts to the cause of this. I am wondering if draining the vapor separator tanks would help. Thanks.

 

[rodbolt]

Re: 2005 yamaha hpdi problem

when was the last VST filter cleaning. when was the last medium pressure inline filter change.
have you carefully checked all battery connections at both ends of the cable for integrity?
are you running 10 micron water seperators with a flow rate of 90 GPH ?
approximatly hour many hours on on the engines ?

 

[Capt Harv]

Re: 2005 yamaha hpdi problem

The engines have 420 hours on them. The VST filters have never been cleaned, nor has the inline filter. Was running 20 micron filters, now 10 micron. Cable connections tight. It strikes me as strange that I can run the engines wide open on flat water with no problem at all. Only when boat pitch-poles over a wave does the problem occur. Makes me think it picks up water for a fraction of a second. Not affected by banging on a wave, so I don't think it is electrical.

 

[rodbolt]

Re: 2005 yamaha hpdi problem

look in the marine tech guide under HPDI maint schedule and tell me how far behind you are .
you are describing a fuel or electrical issue though.

 

[IGWT]

Re: 2005 yamaha hpdi problem

Had the same problem with my 150 HPDI, and it was due to the VST filter being clogged. Replaced and it worked perfectly...