Febtober

I have a 2019 F150. Last year while winterizing it, I had it hooked up to the earmuffs, and after a few minutes I got an overheating alarm. I thought that was odd, but I brought out a second water hose and connected it to the flush port and ran it simultaneously along with the muffs and it didn't happen again.

Now I'm winterizing it for this year, and I'm getting overheating alarms after running for about 6-8 minutes or so, even with both connections running.

I'm thinking of maybe changing the thermostats, but it's such a new engine, it seems odd to have to do that. Stranger things have happened though.

For what it's worth, the engine temp gauge on the dash stays in the +/- 125 degree range, which is the usual operating temp. So I guess something else is being measured that trips the overheating alarm?

Thoughts?

offshore2280

did you tape up the bottom intakes? i have a suk 250 ap and i taped the bottom and i noticed the temp rising fast. i shut down and got a barrel to run it in, since than no problem at all. also a friend of mine with a 250 yamaha same problem. he has been using the barrel and no issues.

whodaguy

It could be that your house has a low water pressure at the spicket. Even if you add a 2nd hose it won't increase the water pressure you have going into the motor inlets. That's because you have diluted water pressure from the original hose by opening the 2nd.
Check to see if new homes have been built on your water line in the neighborhood. Your water company should have the the data on new builds. You can also buy a pressure tester and screw it onto your spicket and open the spicket to it's wide open position. Your water company has a range of pressure numbers that you should be in. It can't hurt to check this out and it won't cost you anything (except for the pressure tester).

Shif

Put it in a tank of water. Sometimes Yamahas don’t like to run on a hose.

saln

I tried the muffs on a tlrd150 to test after eliminating water in the efi system and after about 40 seconds/a minute, it still wasn't spitting so I shut it down. Next time I'll run it in a tank.Dont think these Yams like muffs, never got a heat alarm. Had good water pressure, just didn't trust that water was making it to the pump,or anywhere else, to run it any longer.

jim the fish

My Yamaha 225 does the same thing on the muffs. I switched over to a barrel and had no more issues. Get a barrel or tank.

jayyy

My honda 225 was overheating on the high flow dual feed type muffs. Someone here recomended I use the cheap single feed round ear muffs with the metal wire. Worked great, I think it's because they fit tighter. Could also be you have low water pressure.

Boat Hound

Yamahas are notorious for not liking to be run on a hose. Get a barrel

Clinker

I don’t like muffs either and use a water tank - the kind of thing that’s usually plumbed into a house

Dacman

You may not be filling the block completely, the gauge sender is probably not what the engine controls are looking at.
A sender that is not completely immersed in the water flow will read low.
Make a barrel if it doesn’t like the hose.
Or just flush with port engine off.

SJpatg

I have twin yam 150’s , one will run on muffs the other will not , need to use a barrel on the one that will not

saln

Maybe there are slight differences in the water pumps precision and their ability to siphon from the muffs?

expidia

Funny, just yesterday I had the same issue! I have a few month old 2020 F40 and was winterizing it in my driveway yesterday. I put on these duel feed muffs I bought a few weeks ago and was letting it run on the hose so the pink stuff I put in the gas tank and the filter bowl would circulate. It was running a few minutes and I suddenly realized there was no pee .
I switched back to my old single muffs and it started peeing again. Luckily, the pee was cold. I switched back to the double feed muffs and it was peeing now probably as the single ones filled up the block. I think it takes strong pressure to get the water to rise inside the outboard and those double muffs had too much water spraying out through the prop exhaust. I switched back to the single muffs and will return the double ones back to Amazon. I don't have strong water pressure. I never had this pee pressure issue with the 12 year old Merc I sold and bought the Yammy.

Update: well I just found my issue besides the low neighborhood water pressure . . . . when I went to package it up I see it says for outboards 50 hp and up (mine is a 40)! Too bad too as its well made and really beefy. No where in Amazon's ad does it indicate what the minimum HP's these muffs can be used on. At the end of the ad it just says for larger HP outboards in small print.
* Amazon is pretty amazing with their return policy. I purchased the above on Oct 12th and it's return eligible through Jan 31st 2021!

Febtober

Yeah I wound up just getting a large plastic storage bin at Home Depot and using that.

sixmassive

1. you shouldn't have to run it for a few minutes to flush it on muffs. there isn't enough water flow, and too many air leaks along the water route from the lower unit. Plus, you have a chance of melting your hub. A minute and you're good. just taste the water from the pisser.

2. the flush connection is not designed to cool the motor. it flushes the block with the engine off.

you're thinking too deep into the salt issue.

Febtober

1. I know. I'm not flushing the engine. As stated, I'm winterizing it as per Yamah's guidelines, which state to run the engine for 10+ minutes while on muffs.

2. I know. That's why as I said, muffs were my primary source of water and I only added the flush port once I saw they weren't sufficient.
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Garett

How did you get a cavitation plate that size? Certainly doesn't look like it's stock. ?

Clinker

Yep it’s stock - It’s well under the water in the photo - not sure what you’re seeing, but I can’t see the plate myself.

marketic

In my experience, different outboard brands prefer different muff styles. The big Hondas seem to like the square muffs and the Yamahas and Suzukis seem to like those small round muffs.

This is due to the curvature and overall shape of the lower units. It’s easy to see if the muff you’re using is the right muff for the job by how much water is escaping out of the edges of the muff once the water is turned on. If there is a visible “hole” where an excess tongue of water is shooting out, chances are it’ll trip the overheat alarm

And if you end up using different muffs for different outboards, mark them so you consistently use the same muff for the same outboard.

On the big Suzukis, once you tape off the lower water intake screens (like on the DF300), a round pair of muffs on the upper water intake ports will work fine....zero over heat.

If they fit a bit sloppy, take a small bungey cord and wrap it on the metal frame of the muffs to tighten down the bend in the muffs.

Fishinado

The Yamaha F150 Owner’s Manual specifically warns not to run the engine while using the flush-port.
It will cause overheating,... even in simultaneous use with muffs.... as the flow from the flush port will stagnate the lower unit water pump.