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Random Quote: I'm sure glad I'm not getting all the government I pay for
Heres my overall take - and I'm pretty decent at backyard stuff which being down there seems real close
Get a jack plate - figure out what prop you have and also get the one off the 150 - its probably smaller and it will help get it up on plane faster, 4800 is not good enough.
Get the poppit valve thing fixed and keep what you have, trading for something else will kill you $ wise - also call Yamaha and see what if anything they will send as far as parts, you have pics to send - can't hurt
Get a compression check done you have the tool - my current motor had some water in the lower hole with 80lbs and my buddy pulled the head and got the rings to pop out- I can find out what he used, this was before I agreed to buy it but it worked. I have an original SeaCraft with a 20" transon and I think the guy was using it for skiing and ingested some water in the exhaust. My guy is a 30+ year Rude dealer and knows some tricks, just can't help with Yami parts - they want him as a dealer but at 250K worth of engines and stuff - not in this market
Your motor is way too low, as I stated before, hence the jack plate which will just help it in many ways.
You have gotten some good advice though, many times googens pop in but these guys all seem to know whats going on - the only one I can vouch for is Dunk but all seem to be very good- just an FYI
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The Boaters Mortgage guy
1976 SeaCraft 20 Master Angler/200 Merc XRi
yep, that's all good advice. I am planning to go back down there today, and see if I can build up/fix the place where the poppit valve cover goes. It kinda reminds me of doing a number job on a Harley case....uh, you know. Grind the numbers flat, lay a bead, grind it flat, re-stamp...
at least that's what I heard ....
I will pick up a compression guage this morning. After I put it all back together yesterday afternoon I fired it up and let it run for a few minutes in idle. Well, I actually revved it up a little past idle, and it sounded fine. I just wanted to be sure that I had put all the parts back right, and hooked all them damned wires back up right. Jesus, WHY does an outboard motor need a damned computer and five miles of wire?
Also, I figured that running it a few minutes a day til I get this fixed will keep the cylinders lubed and shiny inside. It's not getting dunked while sitting at the dock idling.
I still do not have a clear mental picture ( what an understatement, generally ha ha ) of where the water is getting into the lower cylinders. I don't think it is being ingested with the intake air. But I don't have a good diagram of how the water jacket, poppet valve thing works, either. I wish I knew that this is the problem, but so far, it's not obvious to me that this housing breaking could also get water into the cylinders.
I agree the motor is too low. And it occurs to me that it's been like this since the day it was installed up in Florida by the original owner's yamaha dealer. So, that poppet valve cover has probably been the most submerged component of the entire motor.
Still, it ran just fine ( except the low RPM) for well over 100 hours before it started this misfiring/fouling thing. I am guessing that is when the original crack in the valve housing started really getting worse.
By the way, anyone have an email contact for "Yamaha" I can write to?
You poppet valve housing has corroded threw. We see this alot with people who do thier own maint and do not realize that it needs to be checked also. You also need to inspect your block anodes as this corr. normally is indicating that they need to be replaced .
On many deep vee hull designs with bracket mounted 25 inch shaft engines I see alot of water intrusion issues with 2-stroke and 4-stroke outboards. The real problem is that when coming off a plane,the pressure that was pushing the exhaust out now for a short time decreases and causes a vacuum that will suck water in to the cylinders.
Some of our regular customers have had us raise up thier brackets 6 inches and extend the shaft 5 inches to stop this from happening
hey, I was just looking up parts costs, and that entire exhaust outer cover, plus the other stuff I would need to replace all this runs about $ 200.
It shouldn't be any big deal requiring a Yamaha mechanic to bolt together a new exhaust cover, should it? I am thinking I might just take this sucker on.
You poppet valve housing has corroded threw. We see this alot with people who do thier own maint and do not realize that it needs to be checked also. You also need to inspect your block anodes as this corr. normally is indicating that they need to be replaced .
On many deep vee hull designs with bracket mounted 25 inch shaft engines I see alot of water intrusion issues with 2-stroke and 4-stroke outboards. The real problem is that when coming off a plane,the pressure that was pushing the exhaust out now for a short time decreases and causes a vacuum that will suck water in to the cylinders.
Some of our regular customers have had us raise up thier brackets 6 inches and extend the shaft 5 inches to stop this from happening
From what I am learning ( and I am on the fast track learning curve right now on this motor) I would agree with you. This housing became the sacraficial anode.
Which block anodes are you referring to? I just ordered the parts to fix this from Boats.net. I am junking the idea of JB Weld, since I can get the parts UPS next day air. $$$$$$$$
And I have just completely changed my entire philosophy on this turkey, after thinking it over. I am going to become very familiar with this motor. In fact, I am now going to be keeping my eye out for another HPDI 300 Yammie.
I figure with the bad rep these motors have, somewhere someone will be willing to let one go cheap, and if I have one backup one in the garage to work on, I can always keep one in good shape on the boat while the other one waits for parts and repairs.
There's really no other way to do it down here. If you want something fixed you basically have to learn to fix it. I can do that. You should see me with diesel Land Rover defenders and GE appliances these days ha ha.
You need to get it running, sell it, and get a 30" in shaft model, or look at extending the shaft.
If you only go that far off shore, you might look at a 30 mph cruise as being VERY ok with an opti 225 and decent gas milage, but new if going with just a single.
Warranty itself, I mean, the practical use and execution thereof, adds little value to me. There's no competent warranty repair here, and I ain't gonna ship stuff slow boat to Florida, and back, for a good dealer to look at it.
Philosophically, the existence of a warranty does tend to assure the customer that the company is standing behind the product, but I know enough marketing to understand the difference between having a warranty and supporting one.
I would opt for ease of repair over anything other than reliability. That's why we drive Land Rovers. Because they are simple, reliable, and easy to fix.
I would opt for ease of repair over anything other than reliability. That's why we drive Land Rovers. Because they are simple, reliable, and easy to fix.
if it was me, i would get the service manual for the motor, and read than sumbitch front to back. sounds to me like an opportunity to learn how to be an outboard mechanic, at least for that motor, as best you can
we are fortunate in the internet age to have instant access to those who can help...i bet you if you asked somebody like andy at SIM to walk you thru this he would do it in a heartbeat
yeah, the internet has helped tremendously, in a lot of things. I have used online assistance to fix the vehicles, appliances, etc. And Andy has been a huge help in the past, even with the other Yamaha, the carbed 150, when I had questions about that one.
I just returned from the boat. I replaced the outer exhaust plate, gasket, and the complete poppet valve ( water control valve ) assembly. Guess what I found? The entire problem was that the factory had installed the plastic valve backwards. No kidding. If you look at this drawing, I am talking about the item labeled 35, which I colored yellow:
See that little plastic valve part? The domed part of it is supposed to be contacting the spring, with the cross shaped piece stuck inside the grommet, and facing the motor. Right? right.
Well, look at this photo, again..
What we are looking at is the flat side of that domed shape, with the x-shaped piece sheared off. The 'x' there is where it broke off the dome shaped piece. The valve was installed, by Yamaha, upside down. It could not have worked right since day one with this motor. The grommet is deformed and pushed halfway into the exhaust water jacket, etc. Its a mess. I have this piece removed now, and have photos if anyone is interested.
But anyhow, that's done. Cost me $ 200 in parts, $ 62 in freight, and $ 21 in import duty. and almost two weeks. Because Yamaha SCREWED UP.
Okay, here's where I am now. After re-assembling all this, I started her up. And she started and ran fine. I let it idle for several minutes, and it was a little bit ragged, but I figured maybe the plugs are a little fouled, or it needs to warm up etc. Hey, I was glad it started! I don't know what I am doing, I had a bunch of stuff off this motor. Whew.
So, I shut it down, and then changed the prop. I took off a bent stainless 15 x 19P three blade and replaced it with a Rev 4, four blade 14 5/8 x 19P. Hey, it just might work.
Then, before headed home, I decided to start it up again. It tried to start, and would not. Sounded suspiciously like fuel starvation. It coughed a few times, but would not start. Then I remembered, DUH, while waiting for parts I had installed a new Racor filter, and a new fuel shutoff valve. And yep, it was in the shut off position. So the motor has sucked all the fuel lines dry.
I tried for an hour to get it to start. I cranked and cranked. I took the air intake cover off, and dribbled a few drops of gasoline into each intake, and yep, it tried to run on that. So I know the problem is fuel starvation. I took the top plastic cover off, and found this Vapor Separator Tank I have heard about. It has a valve like you would find on a tire ( Shraeder valve?) on it.
Can anyone point me to whatever procedure I need to perform to get fuel to the injectors again? or whatever I need to do after running the engine dry with the fuel shutoff valve from the tank closed. Do I need to purge these things of air in the lines or something?
I have been studying blow up drawings of this VST thing. I see there is a filter before it, (strainer), and a needle valve and float inside it like a carb, and an electric fuel pump with a filter on the bottom end of that in there. If nobody has any ideas on what should be the problem after sucking the lines dry, I am thinking in the morning I will start by taking this VST thing apart.
I got some goo, the permatex red gasket stuff. Seems to work pretty good. Not sure about gasoline, but if all I need to do is stick a paper gasket down it should work.
Okay, I have just chugged down a half gallon of iced tea and am back to my usual calm self. I also uploaded some pix I took this afternoon on the boat.
This is what a correctly installed water control valve looks like on the inside of the outer exhaust cover. I know it's correct, because I installed it ha ha...
See how it all fits together? Nice and neat and sensible.
Now, this is the inside of the exhaust cover I just removed, and you can see the grommet was pushed almost all the way into the cover by the improperly installed ( BY YAMAHA!) valve:
And this is the outside of that exhaust cover, showing where the domed shaped valve was pushed against the grommet:
Interesting that the anode installed right next to the valve is essentially untouched. A little surface corrosion. I re-used it.
The valve cover and seat took all the corrosion hit. I just hope this didn't cause something else in the motor to screw up.
Guess I am well started on my new quest to learn all I can about the care and feeding of the Yamaha 300 HPDI. I figure in a year or two, I will be able to buy one of these used for a song, and have all kinds of spares. And I will be the local expert on them.
Thats really the only way to live in a place like this without going crazy. You either have to be willing to spend tons of money educating other people to work on your stuff til they eventually get it right (sometimes never happens), or learn it yourself. I have found it lots faster to just learn how to do it. Usually end up with some cool new tools in the process.
Does anyone know what that tire inflator type valve on the top of the VST is for?
Just reading this thread its amazing to see how much you learned, and me as well. That's ridiculous that the factory installed a part backwards, I would also check to make sure other visible parts are installed correctly as it could be vital.
I might have missed it but did you do a compression check on the motor to check the health of the pistons and rings?
No, I haven't done the compression check. Once I got the parts in hand I was hot to trot hoping this would fix everything. I plan to go back down to the marina in the morning, and will swing by NAPA for a compression guage. (nuther cool tool I need).
When it started, it fired right up, and was running pretty good. After it stopped and I couldn't get it started again, I took out the lowest plug, the one that always fouls the worst, and it was pretty clean. I had sprayed Corrosion X into the cylinders when I knew I was going to be waiting for parts, cranked it over a couple times. I am hoping those are okay. I really don't need to get into the rings yet. This motor only has 150 hours on it.
I am hoping this is something as simple as a stuck needle valve. I still don't have a clear mental picture of how the fuel goes through the system. From the VST to that pump driven by the motor, up top with the belt drive? And from there to the injectors, right? So there is first those two diaphram block pump things, then the electric pump in the VST, and THEN the injector pump? Confusing. why so many pumps to move gasoline two feet?
I have heard that the mushroom end was the new style so sand/rock would not hold the valve open. The way it is in the parts picture it will not do that.
I installed mine with the mushroom facing the motor...the old style BOTH ends look the same.
I have heard that the parts diagram is WRONG and it should face the other way.
Thank about it, why redisign that part, when installed like the picture shows does nothing to keep it from getting clogged.
There are two fuel pumps on that thing. One pumps it up to about 70 psi, the other pump, the big belt driven one on top, pumps it up to 1700 psi. High Pressure Direct Injection. At lest thats what it is on my 200s. I cant belive you never had the overheat alarm go off!! When I bought my 2 Yamis we had to replace the water pumps housings and all of the little spacers and washers and stuff that the dealer I bought them from forgot to replace when he seviced them. Its amazing how much of a difference a washer kit can make! Good luck gringo, pretty soon you will be the TCIs premier Yamaha mechanic!
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