150 HPDI Cutting out

[us010144]

Questions for those in the know:<br />2001 twin 150's w/fuel mgmt. problem is with both engines, about 390 hrs on each. Seem to run fine at cruise speed regardless of rpm. Though regular cutting out if i hit throttles hard and/or hit a wave. Engines do not die, just sputter and then resume current rpm's, alrms do not sound.1. High Pressure Fuel Belt issue? Looks is very good shape? Fuel filters? High pressure fuel pump? No water in filters...plugs are fine. Starts fine, idles ok, just sputters per above. They sputter independently, but happens to both. Two fuel tanks, fuel is ok.

 

[rodbolt]

Re: 150 HPDI Cutting out

check the electrical connections at the battery aand the starter. some had a sleeve that would prevent the lug from making contact with the terminal on the starter for the power feed wire.<br /> also when was the last service of the vapor seperator and the medium pressure filters?<br />sounds like one of them could be clogged.

 

[us010144]

Re: 150 HPDI Cutting out

Don't think vst or med pressure have been serviced. Which one is medium pressure, is that just above VST? And what is required for VST service? Manual makes general reference, but does not show any detail. I'm on the water and dealer isn't, if possible I'd like to do these myself, but obviously want it done right! Thx for prompt reply rodbolt!

 

[rodbolt]

Re: 150 HPDI Cutting out

the VST filter will require dissasembly of the VST tank. it can be done on the water. the medium pressure filter is the inline filter just above the tank. will require a filter, band clip and a speacial set of pliers to replace. some shops use hose clamps but yamaha and merc specifically reccomend against this as worm type clamps will cut into the rubber over time and become loose. a 50 psi fuel leak is not wanted. part number for the pliers from snap on is YA3080. or from mercury 91-803146T.

 

[us010144]

Re: 150 HPDI Cutting out

many thanks! fingers crossed!

 

[us010144]

Re: 150 HPDI Cutting out

Also, is there a filter inside VST? By the way rodbolt Kitty Hawk is my street on frmr GNAS Glenview.

 

[rodbolt]

Re: 150 HPDI Cutting out

yes there is a filter inside the VST. its on the medium pressure pump. test the low pressure pumps for leakage as well.<br /> I flew out of NAS glenveiw a few times when stuck in great mistakes for a year .

 

[John from Madison CT]

Re: 150 HPDI Cutting out

My Ox66 hesitated and lost RPM's for a split second when hitting a wave.<br /><br />I diagnosed it as being a clogged VST filter. It was replaced and she now runs like a champ !!

 

[us010144]

Re: 150 HPDI Cutting out

Thank you Rodbolt, a belated reply. Motors were cutting out in waves and also with increased throttle. Replaced both vapor separator filters and medium pressure filters. Boat runs rock solid now and am back on the high seas! Thanks again!!!

 

[rodbolt]

Re: 150 HPDI Cutting out

aint maintenance great