Running yamaha on hose

b0mbtrack

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I've got a Yamaha Z250TURB HPDI 2 Strk. I tried to run it on the hose connection that is connected to the engine (not using the ear muffs) and it took the water fine but there did seem to be a lot of steam. I then tried to hook up my antifreeze bucket to the hose connection and it wouldn't take the antifreeze.
My two questions are, is it important to run this engine on antifreeze or does it self drain and will running it on this hose connection and not the ear muffs hurt the impeller in the drive?
 

drewmitch44

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Re: Running yamaha on hose

Im not 100 percent positive but im pretty sure if you run it like that you can burn the motor up. The hose connection is for a garden type hose to connect to it in order to flush the motor out. If you want to run the motor you have to give it water for cooling. If you just hook up a hose to the flush connection, that is so you can flush the motor without running it. Anytime that you run a outboard you have to give it water for cooling. Its water cooled so water runs through passages that cool the block. If my memory is correct that motor has the flush connection is not down near the lower unit. If you want to run the motor out of the water you got to run it on the muffs or in a tank or on the lake. What you are talking about will at the least burn up the impeller, but its not good to run it like that. I would pull the lower unit and check to see if you burned up the impeller. I just hope (for your sake) you did not do any more serious damage to the power head. If im wrong someone correct me. But from what am to understand the flush connection is for flushing the motor and not cooling.
 

b0mbtrack

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Re: Running yamaha on hose

thank you i didn't know it was just for flushing, woops. I do know i didn't let it run long enough to overheat the powerhead (top of cylinders were still just a little warm), it was for a very short time that i ran it but i will check on the pump impeller like you said.
Should i bother with the antifreeze, or do these self drain?
 

MnRiverman

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Jul 17, 2005
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Re: Running yamaha on hose

From another BB:
I spoke with a guy named Mark at Yamaha Corp. in Atlanta, GA and here is what he says is the official answer about how to properly flush a Yamaha engine.
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.
 

drewmitch44

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Re: Running yamaha on hose

i disagree tc. If you run on the flush connection then the impeller is spinning with no water. Even a minute or 2 without water could cause the impeller break apart. That is bad business. In my experiance that has not happened, but you cannot just run the motor without water on the impeller. the guy was saying that he was seeing steam tc. Thats not good! that means its not getting enough water and something is too hot.
 

drewmitch44

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Re: Running yamaha on hose

I just read the 2nd part of your post and you are saying that he should just try it out and see if he gets the overheat alarm? That dosent seem logical to me. To me the last thing i want to hear is that alarm. Sometimes even when you hear it its too late. Its not there to see if you can try things out. Its there so you have a chance of not tearing things up. If i ever heard my overheat alarm go off id be worried out of my mind. Id have compression tests done and the whole 9. I just dont think that cooling the motor is a thing that you should just try things out and see if the overheat buzzer goes off. IMHO
 

drewmitch44

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Re: Running yamaha on hose

bombtrack im not sure how yours drains. I dont have the flush valve. Mine i just let the water drain out by tilting up and down a bunch of times. Then i take the t-stats out and leave the housing off whyle i tilt up and down a few more times then leave it all the way down for the winter. I have not had a problem this way. I replace the t-stats before not just leave them out. I think with the flush connection there is 1 more step you have to do. I was asking the same question about the antifreeze as well a week or so ago. Seems pretty divided as far as what people do. I know a lot of people do not use it including myself. It seems like a good idea though but im not going to do it. I had mine all winterized and a couple of nice days came about so i now have to do it again lol. I couldent help myself i just had to go! Ohh by the way is your name from the Rage Against the Machine song?? Just wondering cause that is a bad *** song, album, Band!!
 

b0mbtrack

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Re: Running yamaha on hose

hey drew, yes that is from rage against the machine. great band i was lucky enough to see them in concert before they split up. I always liked their first album, the others after that were good but not as good i thought.

The water did come out of the weep hole on the lower cowling so i'm asuming the water itself went through the engine but not the antiefreeze. The garden hose did have pressure so i'm sure the enging is ok like i said it didn't feel hot at all and no alarms sounded and it was a very short time that i ran it for. The "steam" might have been rich oil mix as engine was cold.

as far as the antifreeze not going through it, i'm going to just guess that it will drain but i will blow back through the weep hole with a small amount of air pressure just to blow out any water that might be there.

thanks everyone
 

drewmitch44

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Re: Running yamaha on hose

I saw them in concert also. It was rage and wu-tang clan. Not the best gathering of people it was fun though. I saw them in philly at what used to be called the e-center Its actually in camden NJ just over the bridge.
 

b0mbtrack

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Re: Running yamaha on hose

thats funny, i also saw them with wu-tang. i hated having to sit through wu-tang but it was worth it to see rage. It was at madison square garden, after wu-tang left a bunch of us got out of our seats and stormed towards the mosh pit. we were able to get over a few fences and into the mosh pit. lots of fun. Zach fell on stage and hurt his ankle during the show but they still finished it up. i wanted to see them when they got back together a month or so ago but i just couldn't find the time.
 
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