Submerged 250 HPDI

Good morning all

4 weeks ago i was the happiest man in town when i bought my 2005 250 HPDI with 84 computer logged hours on her. Spinning a 25 pitch ballistic 4 blade i could jump on the plane in 3 seconds with a fully rigged tournament boat and could reach a top of 76mph fully loaded. To my dissapointment one afternoon late while out fishing the motor came clean of my outmount at around 65 mph. How she came off is more than a mystery but we managed to recover the motor after 4 hours and the only thing that kept her hanging on the boat was pure luck and the ignition harness.

After i recovered the motor that night a opened up and cleaned out all the electrical components and took out the plugs and got all the water out and started the motor according to the procedures i followed after searching the forums for help. Now a week later the motor is running but was missfiring at the bottom and had no power until you ran at WOT but woul not reach full rpm and surged at part throttle. I again cleaned out all the plugs and electrical connections and found that some still had a bit of water in them. After that the bottom end miss was sorted out she ran fine for one day and i took her out again this weekend and now she pulls like a 200 Hp with no real grunt like she had before.

Can anyone of you guys help me out and maybe give me some advice as to what i should look for ?

Thanks and cheers

Rudie

Re: Submerged 250 HPDI

Is it possible that someone was attempting to steal your motor and had not completed the job?

Re: Submerged 250 HPDI

if it went down in saltwater go ahead and junk it. if it went down in fresh you may get lucky.
in the meantime clean all the filters replace the inline medium pressure filter using the correct clamp NO worm clamps and clean the injecctor screens.
there are two filters in the high pressure pump that are technically non-servicable.
but now your at the point that low pressure,medium pressure and high pressure fuel need to be verified as correct.
did you drain and clean the engine oil tank as well ?

Re: Submerged 250 HPDI

First of all BruceAML , that thought did cross my mind and it is the only explanation so far that we could come up with.

Rodbolt to answer your question , I did drain the fuel reservoir at the fuel pump and drained the oil tank at the motor before staring the motor. I will order the filters from my Yamaha dealer but i did notice something else while i was working on the motor this afternoon. I did clean and replace all the damaged plugs the next day but i must have somehow missed the plug on cylinder No5 or it could have had a small crack that opened up a bit more from running the motor this past week. The plug is cracked from top to bottom and I am sure that I am loosing a large ammount of spark through this electrode. I am taking her out again this afternoon and will verify later if it turned out to be the problem.

As for cleaning the screens this is something I have not done before and I have shopped for a Manual but can't find one for the HPDI's. Will this screen be before the fuel injector inside the fuel rail or is this a job best left for a agent. I have a diagnostic report from my dealer and it verified that everything with the fuel system seemed fine pressure wise.

Thanks for the reply

Re: Submerged 250 HPDI

a cracked plug will definately cause a running issue.
the screens for the VST and injectors can usually be cleaned, sometimes replacement is the only option.
gasoline and water tend to make a gel that wont pass the filters very well.
my advice is to inform your insurance company and allow them to make a decision. there are a lot of very expensive electrical parts on that engine.
did you remove and thoughly clean the starter?
that alone is worth about 600 dollars.
if not cleaned it will most likly fail.

Re: Submerged 250 HPDI

Just wondering........does insurance cover this sort of thing? I see you're in south Africa, and insurance policies may be different down there, but are you just out of luck or covered?

Re: Submerged 250 HPDI

Get ready to replace the injector drivers. Yamaha use to say they are a sealed unit and water cannot enter until I opened one up and sent them a picture. There is a small pin hole used for venting and water will enter the units. Also the wiring harness, starter and justr about everything electrical will have to be replaced. Like Rodbolt said, dump it.

Re: Submerged 250 HPDI

I did take the starter off and had it cleaned , i also noticed those two small pin holes on the injector drivers but there was luckily no water that entered that i could see. I put her on the water again yesterday afternoon and she is running like the day I bought her.

I hope that luck is on my side and nothing breaks in the future. Thanks for all the replies and you have been a great help. The only thing i need to figure out now is why the speedometer stopped working but I am sure that wont be rocket science.