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Glad you were able to take care of it and now you have such a well equipped and accessible work area to maintain your lifestyle in the future.
Quote:
Originally Posted by Gringo
Oh man, I have run into a pack of information junkies! (join the club)
Okay, to distill this down as much as possible...I have found three basic problems with this HPDI 300. The process of finding and addressing these problems is the main part of this thread. Finding these problems took me WAY longer than it would have taken a good Yamaha mechanic familiar with the HPDI. No doubt about that.
But I don't have the option of letting a good Yamaha mechanic familar with the HPDI work on it. The Yamaha guys here concentrate on standard 2 and four strokes that come here from Japan, and do not sell, train, repair, or stock parts for HPDI motors built for the USA market.
So this is a story about an average kind of owner/operator living in a third world country, without tools, training, or local support, forced to educate himself on the workings of the HPDI motor.
Problems?
1. Initial problem was motor running ragged, dropping from 5000 to 3000 RPM. I found that the two lower cylinders' spark plugs were heavily fouled, and people on this forum and Andy from SIM confirmed from photos posted here that the fouling was consistent with salt water getting into the cylinders. Hence the thread title.
I found that the water control valve housing on the exhaust cover plate had rotted/corroded completely through. There are photos on the thread. The "poppit" valve was essentially a block of aluminum oxide, and seawater was gushing through the cracks in the housing and dousing the inside of the motor cowling. The water level in the bottom of the cowling was high enough to splash into the intakes for the lower two cylinders. Compression tests showed that the cylinders/pistons/head configuration was still intact. I ordered parts from the USA and replaced the exhaust cover and all water control valve parts.
2.) After curing the water intrusion, the motor would still not get up to WOT. It would approach it for a few seconds, and then drop back off to a lesser RPM and run really ragged. Through a lot of trial and error and various tests, it appeared that fuel quality was the culprit. These tests comprise the majority of these pages of posts.
Again, it took me longer than it would have taken a real mechanic, because I am definitely on a 'learn-as-you-go" program here.
I looked at injectors, coils, spark plugs, and filters and fuel pumps and various other suggestions during this process. After all was said and done, the quality of the fuel was the number one suspect. I ended up giving the fuel to some local construction workers, and we siphoned as much as we could get out of the boat tank via the fuel line pickup.
I ended up getting very familiar with the fuel system. I junked the Perko fuel filter that came with the boat, and installed a Racor 10 micron fuel filter/seperator, followed by another Racor 3 micron filter/separator in the bilge. I am now filtering the local fuel through a 29 micron funnel, then the ten micron and then the 3 micron fuel filters before it ever gets to the motor. So far, this seems to be doing the trick.
3.) Last problem discovered is that although the motor will now get up to 5200 RPMs, it will run that way for a few minutes at WOT, and then shuts itself down to safety mode because of overheating. I had raised the motor all the way up on it's mount trying to keep it out of the ocean when running the boat, and thought that perhaps I had raised it too high. However, I took the water pump apart and it appears that the impeller is not up to snuff. I have one on order from SIM.
So, that's it. So far.
What do I think happened? Well, okay here goes.
-I think the poppet valve was mis installed at the factory. They got the spring wrong or something. I blame that on Yamaha.
-I think that the fuel issues are a little more complex. I think that the boat tanks previous 14 years in south Florida built up some stuff inside the fuel lines and tanks, and as long as the same fuel was being used it was not a problem for the motor. However, this may not be the case. The previous owner went from a 250 non HPDI 2-stroke to this 300 HPDI and had only put about 80 hours on it before shipping me the boat. It may well be that the fuel issue just happened to me another 70 hours down the line.
I think that the fuel down here sucks. It varies greatly from source to source, and comes with god knows what for additives and alcohol in it. I suspect that the sudden change to local gasoline may have loosened up some of the build up scum in the fuel system. Different chemicals, probably more alcohol. Solvents that the system had not seen before. I have no proof of this.
I found out that the HPDI has five fuel pumps, and a total of seven various filters and screens in it before the fuel gets to the injectors. Pressure at the injectors is up to almost 1000 psi. So any kind of dirt or clogs in the system can really affect it. The motor is finicky about fuel quality.
IF the poppit valve and all the filters had been changed on a regular maintenane schedule around 100 hours, it might have prevented a lot of this. HOWEVER, that is not a lock. There are four little screen filters in the High Pressure pump that do not even show up as part numbers or serviceable items in Yamaha's tech manual. Thanks to another forum member, I was able to find and clean these out, and they did need cleaning out.
As an analogy, I think maybe that the sudden change to the gasoline imported here caused a bunch of fuel clots to loosen up and clog up filters down the line all the way to the HP pumps. Getting all that cleaned out is what took most of the time. It was complicated a bit because I did not know if the water ingestion problems were interrelated, and this all started with fouled plugs... These fuel starvation symptoms could have been caused by a faulty electric fuel pump, clogged injectors, bad HP pump, bad boost pump, air leaks...and all of these had to be checked out to eliminate them. Takes time, for a one-man band shade tree mechanic.
So, in summary, I have added two aftermarket fuel filters to the boat, and replaced the VST screen and mid-pressure canister filters on the motor. I have removed and cleaned out the little no-name screens inside the HP pumps. I will no longer fill the tank and let it sit for any length of time, I am putting in enough fuel for the day, and that's it. I have the impeller on order.
I found out yesterday that if I keep the RPM to around 4000 max, the motor doesn't overheat. I will run it back up to WOT after I get the new water pump parts in.
Whew. Some synopsis, huh?
Oh yeah, I have gotten a bit of an education on the care and feeding of the HPDI in the process. Had to buy some tools and diagnostic software.
Wow. can't believe this thread made 30 pages. Thanks for all the encouragement, suggestions, and support.
It took a long time, but this has not been the only project on the plate. I think it was the wife who figured out that we are averaging about one new repair added to the list every day. Some are high priority and set the others back a bit. For example, the transmission brake on one of the Land Rovers froze up and I had to completely take that apart, clean it up, and reassemble it. Stuff like that goes on all the time here. It's really amazing the difference between living in New England and in a climate like this. No freezes. The bugs never die. cuts don't heal quick. Plants never stop growing. rust never sleeps.... a warm, high salt, tropical climate seems to accelerate decay across the board.
To do all this HPDI stuff over again, if I had the parts, would be just a few days next time. In fact going forward I would expect the gating factor to be waiting on parts to come down from Wisconsin... So I guess I learned quite a bit. Haven't had to mess with any sensors yet, I would assume they start failing at some point. But I think this diagnostic software should be a big help there.
Don't know if it was mentioned I really only read the summary. I had the same issues with RPM failure while down in the Keys. Everyone said fuel, filters, ethanol, etc., changed VST and all filters even though they all looked clean. Ended up being a partial block to the reserve oil tank that would cause the motor to go in and out of gaurdian mode depending on fill level. Otherwise no problems on my 300 HPDI 480 hrs.
yeah, Andy (SIM) has told me to check that oil tank level if it happens again. I am going to try about a 40 mile round trip run on Saturday, so should be able to see how well it runs. It won't be WOT of course, knowing it would overheat until I get a new impeller in. That won't be for a couple weeks yet. But I should be able to run it 4000 RPM from what I have seen.
Where was the blockage in your oil system? That's something else I can check while waiting on the water pump parts.
Well, all the new photos I have at the moment (since last blog post) are basically a couple sunsets and some DIY stuff on this computer desk I am building. Not a lot of pretty blue water stuff, yet. We did run out and grab a mess of conch on Sunday but didn't take any photos. Saturday, if the weather holds ( a late season hurricane just formed south of us) we plan to boat over to Pine Cay and then troll offshore outside the reef to see if we can't snag a wahoo or something. Wave height presently forecast to be about six feet. That should be good for some pix. Will be the first extended trip in the Contender since this all started a couple months ago.
You want photos of a table I am building, or you wanna wait for Saturday's boat trip?
Well, I'll probably enjoy whatever you post. The trip to Pine Cay sounds awesome. I finally found a place to rent a boat to go to that area and wound really like to see some pictures of that area. So best of luck fishing and hope to hear from ya'll soon!!!
Hey Dillard there are tons of Pine Cay photos throughout the blog. We go there more than any other island than Provo. Anyhow, I just stuck some photos up on the blog, anyhow. It had been a couple weeks.
And Reelax isn't kidding about the fuel issues with HPDIs. man, that's an understatement. If they are picky about US fuel, imagine what they think of the stuff we get here. I don't think some of the marina fuel we see would be accepted in the USA.
Where was the blockage in your oil system? That's something else I can check while waiting on the water pump parts.
Ours was clogged at the filter coming from the main oil tank under the deck. Very clogged it turned out and wouldn't fill up the tank on the motor fast enough to avoid the alarm. Figured it out with some help from the THT folks and process of elimination.
there are entirely too many filters associated with this motor. Can these things be converted to run on propane? Thats the only chance I have down here of a clean fuel.
Are you guys talking about that little bitty inline filter in the oil line next to the main tank?
In the process of checking stuff out, I am getting all kinds of things fixed. Got the baitwell pump working yesterday. That was a thru hull fitting totally clogged with pieces of shells etc.
Last night playing with the tabs, I noticed a small problem. Like, the motor runs and one tab moved a little bit, sluggishly. So this morning I crawled up under the console and am learning the Bennett trim tab system. I was familiar with Lenco from my other boat. Anyhow, got it all apart, and that resovoir that is suppose to have about 22 oz of ATF in it has aprox. zero ounces of oil in it. Y'all reckon that could account for the fact that the tabs don't work?
I had wondered about them, they seemed not to do much. now I know why. I'll fill it up, and find the leak. I assume there MUST be a leak.
Anyhow, got it all apart, and that resovoir that is suppose to have about 22 oz of ATF in it has aprox. zero ounces of oil in it. Y'all reckon that could account for the fact that the tabs don't work?
This is getting good. When your done with this issue can I request a DIY Provo repair on a bent prop blade?
Well, I cleaned up the resovoir, did the test on the various wires ( it's in the Bennett manual which I found online) and filled it with oil and re-installed it, and hot dang I got trim tabs now.
The very sound of them operating with the hyd pump running is different, of course. And now I realize that I actually have NOT had full tab deflection all this time. For a year now. I mean, I just thought the tabs were slow and didn't have much effect on this hull. Now I know that they were only moving a fraction of their full throw. I can't WAIT to put this puppy bow down into some chop now....
Should gain me a couple inches of draft too...
I cannot find any leaks, though. I am at a total loss as to what happened to almost a quart of Automatic Transmission Fluid that MUST have been in there at one time....
ATF doesn't evaporate, does it?
I just realized I haven't posted any photos lately. Today's exercise wasn't very photogenic, and my hands were covered in transmission fluid. But before I got started today, I was up paying attention to what looked to be a pretty good sunrise developing...
But then the sun came up and wiped it all clean...oh well.
I just ordered a new camera, so I should be able to do a better job of these in a week or so.
Should have some running boat photos after tomorrow. And I hope I have a YFT, or wahoo photo to go with them.
Gringo, I think if you were given a brand new boat you wll go bonkers. You seem to be very much like myself in terms of needing to stay busy. You will always find something to do even if there isnt. Keep it up. I may get rid of my new boat and persue a project since Im bored. LOL.
No, I am actually quite lazy. I would LOVE to just hop in the boat and fire it up and have everything work. I would like for the two Land Rovers and the house to be the same way.
This stuff breaks down continuously. And I just have lost all faith in local craftsmen, technicians, and repair guys. Totally. We've been totally disappointed repeatedly. They charge top dollar, and I can guarantee I won't be happy with what passes for acceptable to them.
I could name maybe three people we have dealt with here that I would recommend to someone else. That's not very many endorsements from someone who has lived here four years, imported three boats, bought three vehicles, and built a house.
So best of luck fishing and hope to hear from ya'll soon!!! 
