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Went out about 8 miles to pick up some conch today. HPDI running sweet.
Gringo....you gonna give us the short n' sweet? Or do I have to read 29 pages to get the final conclusion. I have a 200 hpdi and would like to know what to keep an eye on, just incase. What was it doing? What was the fix?
Went out about 8 miles to pick up some conch today. HPDI running sweet.
What? No no no Gringo ! I would not take HPDI running sweet ,for all this posts ?come on elaborate ,don't make me go down there and perform some water boarding on you, for the rest of the guys here on THT.
Glad it's finally back up and running well. You are officially the Provo HPDI expert mechanic. Maybe you can start fishing again instead of troubleshooting your outboard. Enjoy the sweet running boat.
...... don't make me go down there and perform some water boarding on you, for the rest of the guys here on THT. ]I'll give you until tomorrow ,or else.
Yeah, it's only a little jog from Gitmo to Provo. We could get a few experts in there.....
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...I can't believe this is coming to an end. I knew you would persevere through and fix it at some point...but here it is.
Gringo, I imagine you have probably helped others on this forum tremendously by detailing the troubleshooting you have done on this motor. Thanks for taking the time to document it so thoroughly...now go use the boat!!!!
Now I just have to remember to check the two little Racor drains each time I take the boat out. Not a big deal, actually. Takes about thirty seconds to open the bilge hatch, put a jar under each drain, and open it.
And I fully expect that at some point the motor will start having problems again reaching and maintaining full WOT RPM. But this time, I suspect it's going to only cost me about $ 25 for a new Racor filter and take all of five minutes to fix.
hey, if we get a few more posts this thread will have made 30 pages!!
I would have given up a long time ago. You are to be commended for sticking with it make the repairs. You really didn't have much of a choice living in paradise like you do. I am sure you can fix just about anything.
Gonna stay with the Contender now that its sale able?
No, once I get the water pump kit installed I am going to start actively trying to sell it. I want to be able to take a potential buyer on a ride at WOT. That's when the Contender hull really shines...'fast and on top'.
Still looking at smaller boats. that 20 ft. panga skiff from Panga Marine is looking pretty interesting.
Other two still on the list are the Caracal and the Twin Vee fish and ski, or whatever they call it. the one with the dual consoles, a walk through.
Good to see you stuck with it to the end (fingers crossed). You will probably find that in time, by using those types of fuels down there with the additives (solvents/Ethanol) that eventually they will losen all the muck from the tank and lines. May take time and lots of filter cleaning but in the end should work out fine and the tank will be squeeky clean.
Thanks. I was working on the boat today ( unrelated issue, new bilge switch) and checked the two sediment bowls on the Racors. They had maybe a teaspoon of what I assume was water in them, and some little black flecks, but other than that, pretty clean.
