# Yamaha 150 2stroke flush



## Pinfish Killer (Jun 14, 2010)

I pulled the boat out last week (21ft Sea Pro w/1999 Yamaha CX150 two stroke) and cleaned it up. One of the things that I did was to hook up a "ear muff" type water flush connector to the motor and flush the engine with a garden hose. After turning on the motor and water (at moderate pressure), it took about 15 seconds before the water came out of the water discharge outlet of the the engine. The motor was run at idle while the water had a steady discharge stream for about 3 minutes. At about the 3 minute mark the engine alarm comes on indicating an overheating issue. I shut the motor off and disconnected the water hose. My question is it common for the engine warning alarm to come on during this flush? I was getting a steady stream of water discharged from the motor and it was only run at idle. The boat will sit for a week or two at a time between fishing trips and wanted to flush it between trips. But am I causing damage to the engine doing this? The boat is run in salt water exclusively and I am worried about corrosion issues so I wanted to flush it out when possible.


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## Ocean Master (May 20, 2008)

Use the dual feed flushing muffs with the water on all the way. You shouldn't have anymore overheating.


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## marmidor (Mar 15, 2008)

I have a 2003 Yamaha f225 fourstroke on my 21 Cape Horn that WILL NOT run on the ears. I changed everything to do with the cooling system that I could and it still gives me a horn on the ears. It will sit and idol ALL day without a problem. I'm just going to get a plastic drum and cut it off high enough to cover the scavenge plate and see if that helps.


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## buckhunter32175 (Mar 9, 2010)

I have a 2003 F200 and can't run it on the ears either.....my mechanic told me to cut a 55 gallon drum and trim the motor into the drum (full of water) to run it during the winter time. Works great


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## Ocean Master (May 20, 2008)

Yamaha states to run the 4 strokes in a drum but I have never heard that about 2 strokes


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## esenjam (Jan 30, 2013)

Are you using the square muffs or the complete plastic ones from Wal Mart? If the alarm comes on, it's not getting enough cooling. For some reason the square ones don't cover the intakes well enough to provide enough water pressure. I was using those last fall and burned up an impeller. Spoke to the guys at Lou's Marine in GB and they only use the round ones with the metal arms. They even tie them down with some wire to keep them tight. I have twin '97 Yamaha 150's - switched to the round ones with metal arms and haven't had problems since.


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## DAWGONIT (Jan 16, 2009)

my .02:

used to run my old F225s on muffs and through the hose attachment @ the same time per Yamaha mechanics' advice. bought one of the plastic y-valves that each had an on/off control and a short 6' piece of hose so it could reach both the skeg and hose attachment. worked great every time. 

have noticed that sometimes the muffs will produce a solid/steady stream from the discharge, however had friends that used s small ratcheted nylon device to ensure a snug fit and it prevented the alarm.


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## Turtlebait (Dec 3, 2008)

*plastic drums/vats*

I have '95 Mercury 135's and had issues with various muffs(square/round). Got two 100 gallon plastic "vats" from Tractor Supply (9 mile road), put an elevated base of plywood and 4X4's to bring the top of the vats ABOVE the cavitation plate, no problems since. Plastic vats were 50 bucks apiece on sale. - Ric


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## Pinfish Killer (Jun 14, 2010)

I used the square muffs with the metal arms. The alarm only went off for 30-45 seconds and then I shut the motor off. I just had the motor rebuilt this winter (all gaskets including powerhead, new impeller, etc...), do you think I caused any damage to the engine? The motor only has 30hrs on it since the service work.


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## esenjam (Jan 30, 2013)

Pinfish Killer said:


> ....The boat will sit for a week or two at a time between fishing trips and wanted to flush it between trips. But am I causing damage to the engine doing this? The boat is run in salt water exclusively and I am worried about corrosion issues so I wanted to flush it out when possible.


If they're '99 Yamahas they have the rinse out plugs on the bottom left side of the motors. If you just want to rinse after using the boat just connect your garden hose to those plugs and flush for a few minutes. You don't have to run the motor to use those either, they'll completely flush the saltwater out of the jacket. I have seen guys run the motors using them vs. using motor muffs, but I have also heard its not recommended. I would rinse as soon as you can get the boat out of the water. We don't float boats in water, it's more like acid around here. I would also freshwater rinse around the motor tilt/trim, and the hydraulic steering if you have it. Saltwater will pit the stainless steel pistons and cause the hydraulics to leak. Good luck.


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## esenjam (Jan 30, 2013)

Either get the round muffs with metal arms or the double feed ones and run it again. If its peeing strong then it's fine, if not then you'll need to change the impeller or have it done.


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## Pinfish Killer (Jun 14, 2010)

My engine does not have the hose hook up on the engine, I looked for it but couldnt find it. mechanic told me it wasn't included until following year model. Our engine has a production date of Nov 98' but is listed as a 1999. The thing that gets me is that the discharge port gave me a steady, shall I say normal stream of water for 2.5 minutes before the alarm went off. I just ordered the muffs that provide water on both sides of the intake and will give them a try. I just hope I didn't burn up the impeller.


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## esenjam (Jan 30, 2013)

Pinfish Killer said:


> My engine does not have the hose hook up on the engine, I looked for it but couldnt find it. mechanic told me it wasn't included until following year model. Our engine has a production date of Nov 98' but is listed as a 1999.


That's strange my '97's have them, but they're 150's.

[/QUOTE] The thing that gets me is that the discharge port gave me a steady, shall I say normal stream of water for 2.5 minutes before the alarm went off. I just ordered the muffs that provide water on both sides of the intake and will give them a try. I just hope I didn't burn up the impeller.[/QUOTE]

If it only happened once, I bet the impeller is fine, especially if you just had it replaced recently and shut the motor off quickly when the alarm happened. That 2.5 minutes it ran was the thermostat opening and the motor getting up to temperature. If you put the new muffs on and it does it again, you'll need to look at changing the impeller.


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## hjorgan (Sep 30, 2007)

*this works for me*



DAWGONIT said:


> my .02:
> 
> used to run my old F225s on muffs and through the hose attachment @ the same time per Yamaha mechanics' advice. bought one of the plastic y-valves that each had an on/off control and a short 6' piece of hose so it could reach both the skeg and hose attachment. worked great every time.
> 
> have noticed that sometimes the muffs will produce a solid/steady stream from the discharge, however had friends that used s small ratcheted nylon device to ensure a snug fit and it prevented the alarm.


muffs and the hose attachment builds up enough pressure.


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## mitch mako 21 (May 30, 2009)

Saqme with mine, and I have to use the "y" in the hose so I can use the flush and hook up the "flush port" at the same time. On both of my Yamahas ive had


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## pappastratos (Oct 9, 2007)

Here is where i posted the same question, had Yamaha pro answer it:
http://www.pensacolafishingforum.com/f23/yamaha-2-stroke-115-flush-question-144006/


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## TheCaptKen (Mar 14, 2011)

I believe the key word in the initial statement was moderate water pressure. You need to use all the water pressure you have when flushing. Crank up the pressure. Being the engine was pee'ing, the water pump had picked up prime but wasn't getting enough water to reach the top of the head where the sensor is.


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## Pinfish Killer (Jun 14, 2010)

Ok, thanks for all of the input. From now on I will use the newly ordered "Y" shaped muffs with dual flow (water directed to both sides of the lower intake) and crank up the water pressure to full strength.


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## Steve B (Aug 14, 2012)

Just to be clear ... if I flush my 06 150 four stroke Yamahas with water going in from "above" and "below" at the same time, and I'm getting a steady / strong flow, I'm NOT causing any kind of damage ... correct? Thanks.


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