2004 200hp hpdi rpm problems

[office daze]

Motors jump to 5200, then port motor starts dropping rpms, about 4000 is all it will make. I used to be able to get the boat to 5500 after trimming out. Here is what I have done:

ran off separate fuel tank
VST strainer and pump filter (spotless)
new LP pumps (50lbs)
new Plugs
new HP filter basket
new Injector filter baskets
Ran software (borrowed from a friend) and all voltages and pressures are in range, even put the computer on the good motor and everything is almost a match
I then put the entire VST from the good running to the bad to see if it switched motors - nothing, port motor still wont turn up and stay.

Does it sound like a symptom of fuel injectors needing to be cleaned?

Thanks for any help.

[rodbolt17]

could be, what was the reading on the hp fuel rail.
medium pressure is 50psi hp should be around 625 psi for a 2.6l and about 1100 psi for a 3.3L.

[office daze]

if pressure at the rail is the one read on the computer, it was 7 something.

[99yam40]

If you would post the model # he would be able to tell what motor you are talking about.

700 is not good if it should be 1100 and may not be good if it should be 625, but Rod will let you know if he knows what motor you have

[office daze]

sorry - any help is appreciated - other than injectors, I don't know what else to even try! LZ200TXRC

[rodbolt17]

LZ200TXRC is a 2.6L. should maintain 0ver 600 PSI on the HP rail at all times.
its a twin driver system that I have never seen injector driver problems with.
google the yamaha marine thing and look for a dealer with a master tech.
if HP rail pressure is good and the RPMs fail then there is an issue.
only way to replace the injector filters is to remove the rail,

[office daze]

I'll have to keep trying, no **** brick to pay the yamaha dealer with. At least so far the money I've spent has all been on maintenance type items, I'll try having the injectors cleaned and post back if it works - thanks for the replies.

[Dave Blaber]

I have the same problem, did cleaning the injectors help?

[Bayoucat]

At my shop i have been seeing a lot of issues with trash and water since the Gov. has made it mandatory for this county and all surrounding counties to sell (Ethanol) E10-E15 fuel and regular fuel is almost impossible to find! I use Bell Performance Marine Grade MXO ethanol diffuser in my boat always...i recommend it to all of my customers as well over some of the leading brands that are available. Yesterday i did a fuel system service on a 130 Yami i emptied the water separator spin on filter in a pan as i always do to look at the contents and it was real trashy. I could still fill something in the filter after it had sit to drain i cut the bottom of the filter off with a band saw and it had this weird yellowish muck all in the bottom. A friend of mine that happens to work in a Ethanol plant told me Quote: That muck you see is cornmeal!! Hum that explains a lot... Thanks big brother for less fuel mileage more break downs and more preventive maintenance cost. This is good for my business, but it is a crime against all of my customers. Cat @ City Boat Repair

[rodbolt17]

its not e-10.
its the US govt marine stimulous program.
and yes it eats various plastic tanks and draw tubes,especially on skiff type boats with exposed clear poly tanks.
once dissolved in the fuel neither the water nor the solute can be filter with a standard water seperator but it wont burn in the combustion chamber and will clog injector filters.
E fuels are the biggest scam ever jammed down the US taxpayer throat.

[Dave Blaber]

Hi there I am going to try removing the metal filter above the VST and replace it with a 735psi high pressure hose from the VST to the fuel pump

[rodbolt17]

simply replace the filter.
you MUST use an oetiker style clamp.
DO NOT use a standard worm gear clamp.
the VST to HP pump is a 50 PSI line.

[Dave Blaber]

Thanks for that Rodbolt

[office daze]

I sent my injectors off to Brucato - they are very helpful and I highly recommend them. The day they got them Linda Brucato called to tell me that after cleaning, one on the starboard motor was still too lean and 4 and 5 on the port worked fine until they got hot, then quit working altogether. I've already got the rest of the injectors back, and I ordered three new ones, should have them by Tuesday next week. I'm hoping to take a day off and put them back in. I'll let everyone know if it solves my problem completely.

[office daze]

When I changed the strainer above my vst, I bought a pair of tile nips, the good kobalt ones from lowes. The before cutting the old clamp off, I put the tile nips around it and scribed on the nips how much they closed around the existing clamp, this way I wouldn't overtiten the new clamp, it worked out perfectly. good luck to you.

Reid