150 VMAX HPDI Flushing and Running Out of Water

[DSmith1178]

Hey guys. I will have my boat in a few days. It has the 150 VMAX HPDI on it. Just wondering, because it is my first outboard, what is the procedure for flushing the motor and running it out of water. I just bought the dog ears that deliver water to both ears not just the one, so I am assuming that is a good start. Just want to know about the rest. Thanks

[Skeeter Madness]

You don't need the ears on an HPDI as it has a built in flush adapter on the left side of the engine (looking forward). It's simply a light grey hose that is screwed into the underside of the engine cowling. Unscrew it and hook your water hose to the engine hose, but you shouldn't run it much above idle out of the water. It's covered in your Owner's Manual as well. Hope this helps.

[DSmith1178]

Thanks Skeeter....it helps a ton. As a matter of fact, now I can return those $20 ears and buy the real stuff I need......more tackle. LOL. Thanks

[21XDC]

I dont think your supposed to run it on that attachment. I think thats just for flushing out the motor, Mostly for the saltwater guys....

[DSmith1178]

How do you run it out of water then. Do I still need the dog ears??

[Tr21Pd]

yes.... you need the dog ears ...

[Skeeter Madness]

Here's what my Yamaha Owner's Manual says: Follow this link http://www.yamaha-motor.com/ou...board, open 2005, Outboard, 250 3.3L VMAX HPDI and go to page 42. My Dealer also uses it to run the engine at idle. If you guys have better info, please advise.

[Hamfisted]

Skeeter, on page 4-27 of his owners manual it says to use that flush method with the motor OFF. I don't put a lot of faith in anything the lazy SOB's at my dealership do and I certainly don't let them touch my motor. If you're gonna run the motor use the ear muffs, the dual feed muffs are the preferred style because they provide plenty of water volume.

Mike

[21XDC]

Thats what I thought.

[HD]

on mine when I flushed it with the ear muffs I showed no pressure on the gauge, but when I ran it on the built in hose it showed 5lbs at idle, seems like it's getting enough pressure to show on the gauge

[AB]

Running on the hose using the built in fitting does not allow any water to get to the water pump to assure adequete lubrication. That's why they tell you not to run it on the fitting, use muffs to run it.

[Skeeter Madness]

Yeah, I agree with what the OM says about the 150. Curious why that engine will require the ears. Sorry, but I made an assumption that the 150 HPDI would be the same as my 250 HPDI.

Mine shows WP on the gage as well using the hose. I plan to try and contact Yamaha about this issue as this discussion has gone on in the past and I'm not sure that I'm doing it right (or my Dealer either). I know when I asked my Dealer to order me a Yamaha nose cone flush adapter (low water intakes) he convinced me it was a waste of money (and he sells them). If I get through to Yamaha and get an answer, I'll share the results.

[HD]

that's cool I understand ya'lls points, let us know when you hear sumptin

[Hamfisted]

Skeeter you're not wrong! Your OM does say on p.42 that you can run the motor off the powerhead flush port. I think they may have had a flushing problem with the 3.3L motors and the nose cone flush adapters, so they made that change to the OM. Then if you flip the page over to page 44 it says that the motor should be OFF when using that flush port. I think Yamaha needs to QC their pubs a little better and not just throw in an addendum without proof reading the whole pub. So there ya go. The folks with the nose cone lower units (newer VZ guys...) may find both guidelines in their owners manuals. That certainly muddies the water. Anybody using the nose cone flush adapter and having water feed problems or overheats on the garden hose using it?

Mike

[brianalan]

I know what you mean about water coming out every hole in the lower unit. I run my Yamaha 115 on that little hose adapter/flusher and I get 7lbs of water pressure. I have not had any problems and it appears that it is getting plenty wet. When I unscrew the hose, water continues to drain out for almost a full minute.

[Skeeter Madness]

I just got off the with Mark at Yamaha in Atlanta, GA and here is what he says is the official answer to this question:

If the engine has a flush adapter and your water source has enough pressure to cause a stream of water to discharge from the cowling drain (pee hole), then it is fine to run the engine on the flush adapter only, but it's limited to 1500 RPM max and no longer than 15 minutes. This also ensures adequate water for water pump lubrication.

If the overheat horn sounds or you cannot get enough pressure for water to flow from the cowling drain hole, you are required to use BOTH the flush adapter and a lower unit flush adapter simultaneously. Additionally, you should never start the engine out of the water until you have allowed adequate time for the engine block and lower unit to fill with water and start draining out. If water is draining out of the lower unit, it is in fact lubricating the water pump.

Hopefully, this will put this issue to bed. Please don't assume that I'm trying to tell you how to maintain your engine, just merely trying to alleviate all the ambiguity surrounding this issue. I shared with him that their technical data is inconsistent, but he had no response.

[brianalan]

Awesome info! Thatnks for getting to the bottom of it. 15 min. max and 1500rpm max. That helps me. thanks again!

[G3HP200]

thats the same thing I was told!i've doen it that way all the time!Never hurt my 04' vmax150 hpdi.Just don't rev it up.

[rwtzx]

My manual ('05 3.3L) says to run it using the flushing adapter on the motor to fog it prior to storage, and flush it out if used in saltwater. I have 10psi at idle and water pours out everywhere. Thanks for clearing this up SkeeterMadness

[HD]