Yamaha HPDI PRV (Poppet Valve)

[flounderpounder225]

Well my 250 HPDI has never really pee'd a strong stream, but you hear people say thats kind of normal.  She has never over heated in the water ever, but on the hose the temp alarm has gone off once or twice.  So a little research and it turns out this is fairly common on the yamahas, the poppet valve is a big culprit.  and its supposed to be not so fun to get to.  So any experience on this would be appreciated, I think I have the general idea, have to pull the coil packs, and maybe the ECM to get to it, its way down low under the lower cowling edge on the rear of the engine.  I will be posting pics hopefully for future dealinigs, and we'll see how the water pressure changes

[GoneFission]

Big discussion over on THT on this:

http://www.thehulltruth.com/boating-for ... -pics.html  

Interesting thread here on 250HPDIs - note one Yammie dealer says the HPDI motors like to run higher on the transom...  

http://www.wmi.org/bassfish/bassboard/b ... _id=212213  

Hope this helps - good luck!

[flounderpounder225]

Big discussion over on THT on this:

http://www.thehulltruth.com/boating-for ... -pics.html  

Interesting thread here on 250HPDIs - note one Yammie dealer says the HPDI motors like to run higher on the transom...  

http://www.wmi.org/bassfish/bassboard/b ... _id=212213  

Hope this helps - good luck!

Kenny Mann the owner of what used to be Emerald Coast Marine here in Pensacola, and where I got the motor told me just removing the coil pack assy.  would allow enough room, but then he's a yami super tech.. we'll see how it goes.

[flounderpounder225]

Ok trying to get all these pics uploaded, the procedure wasn't all that bad, a few tools that you need to make the job easier, it's all 1/4 drive stuff, a stiff apex joint that will hold the 10 mm socket correctly without flopping, a quality machinist scribe with the 90 degree end, zip ties,it was NASTY! This will definitely be a part of my annual service from now on, and I use salt away every single time, and never run her  up in the sand, but this was shocking.

So here is what your looking at to begin
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After removing the back coil cover Mark the connectors with the cylinder numbers just to be safe
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Here it is, notice I used a zip tie to pull the wiring harness up and out of the way to clear the way to get to the bolt and ease of removing the housing when unbolted

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With the housing removed this is what was revealed, nasty.  Needle nose pliers and the scribe to slowly scrape away the debris locking the valve in its seat, it was completely imbedded in this crap, the valve actually starting breaking apart as I pulled at it, but eventually it popped out use the 90 degree scribe end to pull the old grommet valve seat out

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Clean everything out, I made a small hose to attach to the vacuum and sucked the hose to get debris out of it, clean clean clean. Here is the old poppet compared to the new style mushroom head

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Anti seize on the bolts, and this is an old trick many of you may know, but some may not, when your putting the bolts back in because they are down in the pit, put something in the socket to keep it tight, I just used a piece of the bag that the parts came in, then you can stick the driver in without worrying about losing the bolt into never never land in the boat to cowling

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I put a stainless hose clamp on for reassembly, get the plunger and spring in the hole, align the housing, push in with your fingers while inserting the upper right bolt (held in the socket with something) screw it in until snug, the rotate the housing until the left hand bolt aligns.  

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Now drink a beer and watch the difference in your water pressure/stream

[RickK]

Nice post FP  

[dburr]

Mark that completely rocks!! Thanks for the tips and pictures!!!

[Georgie]

X2!!  

Question...   Did you accidentally use the same pic twice (i.e. the one that supposedly shows the wire harness tied back with zip tie seems to be the same as the one above it??  

That said, loved the good step by step, photos, and tips!  

[flounderpounder225]

X2!!  

Question...   Did you accidentally use the same pic twice (i.e. the one that supposedly shows the wire harness tied back with zip tie seems to be the same as the one above it??  

That said, loved the good step by step, photos, and tips!  

yes, somehow the pic got in there twice, not bad considering I did this at the end of the day, and I might have had a beer or 3  

[GoneFission]

Good post Marc!     Sharing experience is what CAS is all about.