HPDI INJECTOR QUESTION

[flounderpounder225]

Could anyone that has an HPDI possibly take a clear picture of the Throttle Position Sensor, looking in the middle of the TPS bracket and showing how the orientation of the little “lever” in there engages the shaft coupling?  On reassemble mine came apart, I lost the little lever, I have the lever on order and should get it tomorrow, just need a good image of how it all hooks together.  After the reed valve assembly the motor did not want to run right BC my TPS was way out of whack.  Thanks

[Blue Agave]

Good to see you got the reeds all assembled, sucks about the TPS. Do you not have the service manual?  Have you tried an Internet search for the manual?  You may be able to download the manual in PDF form.

[flounderpounder225]

Andy from SIM sent me the whole procedure for setting the TPS, just need to get it put back together correctly and get it set.  Thanks

[flounderpounder225]

Hopefully this is the conclusion of this issue.  Finally got to take the boat out for a few short runs in In the Bayou yesterday.  After getting the TPS installed correctly and getting the voltage set, this is incredible!  I feel that this reed valve must have been broken for a very long time, possibly since I have owned the motor.  Yesterday's run produced an easy 300 rpm increase at WOT, and reduced my GPH burn by 2 to 2.5 GPH at 30 MPH.  I actually had to back the throttle off because it was easily hitting 5800-5900 with my big 15 x 15 inertia prop.  Before if I broke 40 mph it was with a light load, smooth water, and fresh plugs trimmed up to the point just before prop blow out.  Now, 41 is not even WOT.  I have my old yamaha prop from my last boat, which was repitched to about 16.5 from 17.5 , I am going to try it and see what happens, I can definitely stand more pitch now.  Chris Carson reeds are the bomb, I will be calling him tomorrow to report my results, he wanted to know how it worked.  Knowing this hpdi drops 2 at idle it never sounded smooth at idle, now it is so much quitter and smooth at idle and the throttle response is very crisp.  I think based on how easy this was to replace the reeds, anyone should consider this change for performance and fuel efficiency..

[Blue Agave]

Like a new motor, right?

 

[flounderpounder225]

   absolutely

[seabob4]

Sweet Marc!!  Didn't read back in case you mentioned it, but how much did those reed vlaves run?

[flounderpounder225]

$125 plus Tax and ship, I think $147 to the house.   What an amazing difference.

[dburr]

Good to know! You think that a swap from stock to Chris's reeds will be an improvement even if everything seems ok? Just wondering, the OX66 is running fine but any performance increase with an economy boost, especially at that price is worth doing!

[Blue Agave]

Good to know! You think that a swap from stock to Chris's reeds will be an improvement even if everything seems ok? Just wondering, the OX66 is running fine but any performance increase with an economy boost, especially at that price is worth doing!

I would say "Yes".  Based on your signature I assume your motor is 15 years old.  I was not experiencing any problems with my motor, 2002 EFI Merc, but figured that cleaning the injectors was a good idea.  The Merc is a bit different than the yammi and to remove the injectors the plenium needs to be removed, while I was in there decided to change the reeds as well as I already had the plenium off.  Very happy I made the decision to change the reeds. 

 

[flounderpounder225]

Good to know! You think that a swap from stock to Chris's reeds will be an improvement even if everything seems ok? Just wondering, the OX66 is running fine but any performance increase with an economy boost, especially at that price is worth doing!

Based on the ease of installation, and the performance increase I realized.. Heck yes, the throttle response and idle smoothness is instantly noticed.  Is the OX-66 direct injected or throttle body injection?  Never paid attention to the difference of HPDI to OX-66

 

[rockfishon]

I was having idling issues as well on a 2003 Yamaha 150 HPDI.  Replaced filters $$, changed out the low pressure fuel pumps, 3 sets of plugs and them found this thread.  Inspected my reed valves and low and behold, the bottom 2 were broken.  Thanks for posting this thread or I would have never found the problem.  Here are some pics of my reed valves:

https://goo.gl/photos/DgUDog7CoaVMaT9R7

I am going to try to borrow a bore scope to search for the missing pieces since I still have good compression.  I am hoping that they are sitting in the crank area.  I I don't see the pieces, I will take a head off to see if the piston is damaged or scored.

[rockfishon]

Well, I couldn't see much but ended up crushing the bore scope lense/light in the cylinder from the spark plug hole.  Must of got wedged in one of the ports while hand turning the engine.  Not good.  I tried to vacuum it out but nothing came out.  Was told if it ate a stainless steel part that a little plastic won't matter.  Think I will order new reeds and hope for the best at this point.  Does anyone know if I can reuse the intake gaskets or do I need new ones?

[rockfishon]

Ordered new gaskets.  I am have decided to reuse the old intake and reed valve assembly off my spare engine. 

[rockfishon]

The gaskets arrive tomorrow.  Does anyone know the torque for the intake and reed assembly?