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Nice thread. I have the same 2006 motor and i think ill have my poppet valve checked at the end of the year.....Good luck!!
__________________ 2006 Skeeter ZX24 Bay
2006 Yamaha 300 HPDI
2010 Ford F-150 FX4 5.4
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Well, thanks for the link. But I still don't see the definitive answer about which way the valve goes in, stem in the grommet, or stem in the spring.
One guy said that he "heard' that the mushroom seated on the grommet, and then there was that bit about the stem not going back into the grommet if you install it that way. that makes sense,
BUT we have this diagram/schematic from Yamaha that says "do it this way".
I guess I need an answer from Yamaha. Anyone know how to get an answer from Yamaha?
I wouldn't ask the mechanics down here what time it was.
Ask Andy at Shipyard Island Marina on the vendor boards. He will know. I've done this myself on my 250HPDI but don't remember which way the grommet went. Best of luck.
Ask Andy at Shipyard Island Marina on the vendor boards. He will know. I've done this myself on my 250HPDI but don't remember which way the grommet went. Best of luck.
typ yamaha !, an anode right beside the area thats heavly corroded.
that valve is for fuel pressure testing, if you got a factory service manual there should be instructions for repriming the fuel system.
aha! "repriming the fuel system'!! I like the sound of that. Sounds like what I might need. But of course there is no 300 HPDI manual in this nation. I have the only 300 HPDI here, and I don't have the manual.
If anyone is still following this, the education of Gringo continues.
I spent four hours in the sun again today working on that outboard. Man, them brackets on the Contenders sure make it easy to work on the motor.
Without going into every little detail, I have found that the problem is that the electric fuel pump is not pumping. Screen is clean. Float and needle valve in VST are good. Fuse for electric fuel pump is good. I got refried in the sun and finally buttoned it up and came home to regroup and study diagrams. To find out if there is anything else that would prevent that pump from running. Like, maybe a pressure switch or something. Tomorrow, I will go back with a VOM and see if there is indeed 12 vdc on those pump terminals.
Unless I find something in a schematic that might cause it to not run.
And I am developing a growing animosity for the little japanese engineer who put a year or two into those VST shock mounts. holy sashimi, Yuki.... Wouldn't a simple grommet have sufficed??
And I dropped the screwdriver overboard. And went down to get it. Exciting day, huh.
To fill up the VST tank you need to turn your primer bulb arrow up
pump 15 times
then try to restart your motor
the VST pump will not fill up on its own.
Yep, I did that. I don't know if it was fifteen times, though. But after putting it all back together, I disconnected that short little section of fuel line from the top of the VST to that last filter clamped to it, and turned the ignition on. expected to see some fuel come from the hose. Nothing. So I reconnected it and cranked it, still nothing, of course.
Do you know if that electric pump is always on if the ignition is hot? Are there any pressure sensors that could go bad or unplugged ( open) and cut the circuit to it?
I just looked up the price of those pumps, over $ 700 online. Thats a bit harsh already for a motor with only 150 hours on it.
When the key switch is on do you here the pump for 5 seconds???
also take it apart again and check the float
mine was stuck or fell off cant remember
try one more time and get a fuel pressure gauge
connnect to the nipple I think you should get 50lb of pressure.
Do you know what normally shuts if off after five seconds? a pressure sensor somewhere, I assume? Of course I am hoping THATS the component that's failed.
Ok. Now it's Saturday morning. Usually, if I am lucky, I can fall asleep and let my head work on these issues while I am snoozing. I tried that last night.
So, this morning, I am thinking. "What changed'? And what changed (with the fuel system) is that I ran the motor with the fuel valve shut off. And now it's not pumping gasoline out the top of that VST. And the filters are good. And the float is good, and the needle valve is good. And the squeeze bulb fills the VST with gas. (where does the air go when you do that, I wonder? to the air intakes?
So, my head seems to think that either I disconnected something to that electric pump inside the VST, or there is a pressure switch somewhere that tells it when to shut off and that switch has done told it to shut off, or that $ 700 pump suddenly went bad. There was still fuel in the VST when I took it apart, so the pump never did run dry.
I can see where sucking on a plugged fuel line might mess with a vaccum sensor, if there is such a thing. Unfortunately, I cannot find any real info on that little doo dad that is bolted to a plate just under the VST. Maybe that's it. The Yamaha diagrams have THIS totally wrong, too.
So, now I am thinking, next step, put a voltmeter on the pump terminals on top of the VST and see if I got 12 volts there with the ignition on.. If yes, it's the pump. If not, then it's electrically upstream of that. The fuse is good.
Forgive me thinking out loud. Feel free to interrupt.
Hey Gringo!! You are starting to sound like a lot of us other people. Don't trust the mechanics to do it right. Internet research is wonderful. You may not be aware of it but you are in fact teaching a lot of other people how to work on this issue!!!! Great job of passing along information and results, good or bad. When you finish, you will feel just a little cocky having fixed all these issues yourself. AND you may just wind up being the GO TO GUY on the islands for Yamaha Issues! Once you finish these you'll never have to worry again as you will know how to keep up with them!! One question for you! Do you have a water pressure gauge installed? Once you get used to normal readings at all rpm settings you will notice changes in water flow. That's how I discovered about the PRV valve. Even after two different Yamaha Service shops went through it and changed the water pumps! They had no idea about the PRV valve. Go figure. Internet research saved the day! I removed mine and cleaned it off and re-installed it and it solved all the problems. I never saw the cover break before. I am following your thread with great interest as I am learning right along with you!!
Good luck and thanks again!!
Tommy
Haven't been able to get to the boat today. I am too busy fixing things at the house. And despite the fact that I can see the boat from where I am sitting , it's not a quick trip. 900 yards as the crow crabs, but 10.2 miles by vehicle. And 7 of those miles are some really bad road, never been paved.
I am still trying to figure out what turns that pump off after 5-7 seconds. I gotta get a manual, I guess. Of course, that will set me back a week if I wait for it.
oh, yesterday, while pondering the imponderables, I took the pressure valve apart and flipped it around opposite what Yamaha says. Funny how easy these things get after you have done them a few times. But the stem in the spring and the dome seated against the grommet makes more engineering sense to me than the other way.
Where should I start looking to see where the water is coming in?[/QUOTE]
If not the hed gasket you may have cracked block. I have the same problem on my motor. I an deciding to rebiluild or just get a new power head and it seems that a new power head will be cheaper.
If not the head gasket you may have a cracked block. I have the same problem and am deciding weather to rebuild or replace. It seems that replacing is going to be cheaper.
I don't think I have seen any evidence of a cracked block. Why do you suspect that?
And fuel is not getting to the HP pump. It is not getting out of the VST. It ran for several minutes ( with the fuel shutoff valve closed) after I got the poppet valve installed. I don't think it would have run for even two seconds without the HP pump working, would it?
A suggestion.. Bleed some pressure off of the shraeder valve,then turn switch on to see if hp pump comes on with voltmeter attached to pump leads. I have the manual to 0x66 and I believe the VSAT is a bout the same but the hpdi has and aditional pump so I can't help you there. But I found the relay to the hp pump was the problem I had similar to yours.
Unless I overlooked something, the HP pump on this one is belt driven. The VST pump is electric. I could be wrong, I have been trouble shooting fuel issues from the tank an have gotten as far as the hose to the filter past the VST. Gas is getting into the VST, but not out of the VST.
= Google 
Motor issues 
