Overheating Outboard on Flushing Muffs

A

ATPNW

Member
So I just got back from a week long outing at Sekiu. The twin BF50's are still running great. Upon getting home and flushing the port motor, the over heating alarm went off. I was in the cabin and was able to turn off the motor within a second or two. I had a helper out back of the boat who confirmed there was a stream of water coming from the tell tale (although it could have been a weak stream). I was able to get out of the boat, re-adjust the muffs and fired it back up with no more alarm the rest of the time (maybe a minute or two longer). My concern is that when i was done, i noticed the mid section of that outboard was hot. It was more than what i would consider warm, but not hot enough that i couldnt keep my hand there if i wanted. My questions are:

1. Should I have waited longer before restarting the motor after the alarm went off?
2. What should I be inspecting to see if I caused any damage due to overheating?

I suspect there wasnt enough clamping pressure on the flushing muffs, causing the boat to have an insufficent amount of water for cooling.
 
Most likely no damage. The item initially would be the water pump impeller . It is rubber and if no water to lube it, then it may overheat and fail. But since the motor did well after the re-adjustment, and there was some "pee" stream, not likely there was damage.

The impeller should be changed if a decreased Pee and not due to obstruction, at about every 200 hours or every 3 years. I know of some which have lasted 8 years, and others which have failed in less than 50 hours,.

The engine itself should be fine.
 
thataway":1mjazsgi said:
Most likely no damage. The item initially would be the water pump impeller . It is rubber and if no water to lube it, then it may overheat and fail. But since the motor did well after the re-adjustment, and there was some "pee" stream, not likely there was damage.

The impeller should be changed if a decreased Pee and not due to obstruction, at about every 200 hours or every 3 years. I know of some which have lasted 8 years, and others which have failed in less than 50 hours,.

The engine itself should be fine.
Click to expand...

Thank you for the quick reply. I am two years since the impellers were last changed.

On a somewhat related note, has anyone come across a good set of muffs for these smaller outboards? I see they make some with a clamp system that goes through the water intake.
 
One thing to consider when using muffs is the water pressure from the hose. Depending on the pressure you have, your impeller may get quite a boost and therefore may not need to work as hard (or at all) and the motor will still be cooled and you get a pee stream. Once you get out on the water, the impeller has to work unassisted and may not be up to the job.
 
ssobol":1qz4h7pf said:
One thing to consider when using muffs is the water pressure from the hose. Depending on the pressure you have, your impeller may get quite a boost and therefore may not need to work as hard (or at all) and the motor will still be cooled and you get a pee stream. Once you get out on the water, the impeller has to work unassisted and may not be up to the job.
Click to expand...

Thanks, I had read this before too. I typically only turn my faucet about 1/4 fully open. It is had to gauge what amount of pressure that actually equates to. Any tips for finding the sweet spot?
 
With the earmuff you also need volume, even more so if you don't have a very tight seal, and that often equal to high pressure. I sometime use a big trash can full of water, so I know all the pressure is from the engine water pump.
 
I typically only turn my faucet about 1/4 fully open.
Click to expand...

I turn the water fully on. There is some pressure drop, since it is about 75 feet from the hose bib to the motor. Suggested water pressure at the muffs should be about 30 to 40 PSI. Mine is very close to that. There is always some leakage around the sides of the muffs.

Ssobol is right on with the see what the pressure is when you have the boat in the water--with the smaller engines you can usually fit a 5 gallon bucket around the lower unit, and have the hose running into the bucket, to double check the flow.

Also leave the motor at an idle--don't rev it up during "flush". When I have the boat in salt water, then I will use the flushing port (engine not running) and realize that the lower unit and impeller will not get full flushing.
 
If it's been two years since you last changed your impeller, it might be a good idea to change it again now with the overheat.
 
I've had the hose valve half open before, and not enough water to get a good pee stream. I'd open it fully.

I had this same problem once. The 2006 Honda 9.9 just got back from the shop, in perfect condition, running like a top. The muffs somehow slid out of place a bit. When the alarm went off I had stepped away, but turned it off in about 10-20 seconds. Yes, the motor felt "hot", more than usual. Ever since that incident, it was really hard to start the motor. I tried flushing the carb bowl thru the drain screw with crab cleaner. This worked! The motor ran fine. And then it didn't.. .a few starts later, it didn't want to start again.. "My theory" is the the extra heat somehow loosened up some debris in the fuel system. These motors are notorious hyper-sensitive to anything in the fuel line... I think I have to rebuild the carb now...
 
colbysmith":3jxzdvtw said:
If it's been two years since you last changed your impeller, it might be a good idea to change it again now with the overheat.
Click to expand...

Probably not a bad idea, I do have a couple replacement kits ready to go. Thanks for everyones comments here.
 
ATPNW":3768bpxf said:
So I just got back from a week long outing at Sekiu. The twin BF50's are still running great. Upon getting home and flushing the port motor, the over heating alarm went off. I was in the cabin and was able to turn off the motor within a second or two. I had a helper out back of the boat who confirmed there was a stream of water coming from the tell tale (although it could have been a weak stream). I was able to get out of the boat, re-adjust the muffs and fired it back up with no more alarm the rest of the time (maybe a minute or two longer). My concern is that when i was done, i noticed the mid section of that outboard was hot. It was more than what i would consider warm, but not hot enough that i couldnt keep my hand there if i wanted. My questions are:

1. Should I have waited longer before restarting the motor after the alarm went off?
2. What should I be inspecting to see if I caused any damage due to overheating?

I suspect there wasnt enough clamping pressure on the flushing muffs, causing the boat to have an insufficent amount of water for cooling.
Click to expand...

Because there was some water flow out of the pee hole, it was probably good to re-start the motor immediately after adjusting the flushing muffs. You may want to inspect the exhaust manifold for cracks but I don't think you will find any.
One thing I noticed is that you took your boat home to flush the motor. I started out using flushing muffs but soon got tired of having to stay with the motor to ensure that the muffs did not slide or fall off. Now I park the boat over my lawn and use a 100 gallon Rubbermaid Stock Tank filled to the rim and flush both the main and kicker at the same time. https://www.rubbermaidcommercial.com/ma ... ock-tanks/ The motor needs to be in the tank deep enough to cover the cavitation plate. I adjust the pee hole nozzles for overflow to go back into the tank. I attached a 3/4 in. ball valve with a hose thread to drain the tank afterwards while watering the lawn at the same time.
I realize that this method may not be practical or applicable for everyone but if you store your boat at home, this method may be a safe and reliable alternative.
 
When I use muffs I put duct tape over the water intake on the underside of the cavitation plate per the owner's manual. The one time I didn't I got an overheat alarm. Taped it and started back up with no alarm.
 
DayBreak":3gygpwv5 said:
ATPNW":3gygpwv5 said:
So I just got back from a week long outing at Sekiu. The twin BF50's are still running great. Upon getting home and flushing the port motor, the over heating alarm went off. I was in the cabin and was able to turn off the motor within a second or two. I had a helper out back of the boat who confirmed there was a stream of water coming from the tell tale (although it could have been a weak stream). I was able to get out of the boat, re-adjust the muffs and fired it back up with no more alarm the rest of the time (maybe a minute or two longer). My concern is that when i was done, i noticed the mid section of that outboard was hot. It was more than what i would consider warm, but not hot enough that i couldnt keep my hand there if i wanted. My questions are:

1. Should I have waited longer before restarting the motor after the alarm went off?
2. What should I be inspecting to see if I caused any damage due to overheating?

I suspect there wasnt enough clamping pressure on the flushing muffs, causing the boat to have an insufficent amount of water for cooling.
Click to expand...

Because there was some water flow out of the pee hole, it was probably good to re-start the motor immediately after adjusting the flushing muffs. You may want to inspect the exhaust manifold for cracks but I don't think you will find any.
One thing I noticed is that you took your boat home to flush the motor. I started out using flushing muffs but soon got tired of having to stay with the motor to ensure that the muffs did not slide or fall off. Now I park the boat over my lawn and use a 100 gallon Rubbermaid Stock Tank filled to the rim and flush both the main and kicker at the same time. https://www.rubbermaidcommercial.com/ma ... ock-tanks/ The motor needs to be in the tank deep enough to cover the cavitation plate. I adjust the pee hole nozzles for overflow to go back into the tank. I attached a 3/4 in. ball valve with a hose thread to drain the tank afterwards while watering the lawn at the same time.
I realize that this method may not be practical or applicable for everyone but if you store your boat at home, this method may be a safe and reliable alternative.
Click to expand...

Great idea - the 50s will fit in a 35 gallon round garbage can as well. I do that a couple times of year just to flush out the salt. At the end of the season, I add salt away for good measure. And if you don't feel like just idling them, because very little water flows through them at idle...just tossing that out there....you can let them rev to your heart's content and really get a good flush because now you basically have a run tank.
 
DayBreak":20pvhecr said:
ATPNW":20pvhecr said:
So I just got back from a week long outing at Sekiu. The twin BF50's are still running great. Upon getting home and flushing the port motor, the over heating alarm went off. I was in the cabin and was able to turn off the motor within a second or two. I had a helper out back of the boat who confirmed there was a stream of water coming from the tell tale (although it could have been a weak stream). I was able to get out of the boat, re-adjust the muffs and fired it back up with no more alarm the rest of the time (maybe a minute or two longer). My concern is that when i was done, i noticed the mid section of that outboard was hot. It was more than what i would consider warm, but not hot enough that i couldnt keep my hand there if i wanted. My questions are:

1. Should I have waited longer before restarting the motor after the alarm went off?
2. What should I be inspecting to see if I caused any damage due to overheating?

I suspect there wasnt enough clamping pressure on the flushing muffs, causing the boat to have an insufficent amount of water for cooling.
Click to expand...

Because there was some water flow out of the pee hole, it was probably good to re-start the motor immediately after adjusting the flushing muffs. You may want to inspect the exhaust manifold for cracks but I don't think you will find any.
One thing I noticed is that you took your boat home to flush the motor. I started out using flushing muffs but soon got tired of having to stay with the motor to ensure that the muffs did not slide or fall off. Now I park the boat over my lawn and use a 100 gallon Rubbermaid Stock Tank filled to the rim and flush both the main and kicker at the same time. https://www.rubbermaidcommercial.com/ma ... ock-tanks/ The motor needs to be in the tank deep enough to cover the cavitation plate. I adjust the pee hole nozzles for overflow to go back into the tank. I attached a 3/4 in. ball valve with a hose thread to drain the tank afterwards while watering the lawn at the same time.
I realize that this method may not be practical or applicable for everyone but if you store your boat at home, this method may be a safe and reliable alternative.
Click to expand...

I have considered this, but my question would be - How would you then use Salt Away? Or do you not use it?

Edit: I now see T.R. Bauer's suggestion with the Salt Away. I think ill try to incorporate this. Thanks!
 
John&Robin":3h3sd4ra said:
When I use muffs I put duct tape over the water intake on the underside of the cavitation plate per the owner's manual. The one time I didn't I got an overheat alarm. Taped it and started back up with no alarm.
Click to expand...

Thanks ill try this next time!
 
Full disclosure....for the last couple 3-4 years I have been using CRC Salt Terminator because it is available at Amazon for about 40 bucks per gallon. Salt Away is double the price (or more) for some reason. It's sort of different...flows better....and Salt Away puts on a better suds show, but I'm not sure the suds show is actually worth the extra bucks and has anything to do with actual salt removal. I have 5 outboards to do, so I just keep moving the roughly 1/2 to 3/4 full 35 gallon garbage can from engine to engine giving them a good flush. Because I use the garbage can I am able to use warm water too - should work better than cold water.....my hands don't get cold anyway....lol....I bought their mixer once too, but it is not very good. In fact, unless they have changed it, it's just plain crap - leaks everywhere.
 
ATPNW":23euvvyq said:
I have considered this, but my question would be - How would you then use Salt Away? Or do you not use it?

Edit: I now see T.R. Bauer's suggestion with the Salt Away. I think ill try to incorporate this. Thanks!
Click to expand...

To use a product like Salt Away you will need muffs and a mixing unit unless you pour a lot of the product into the tank. https://www.westmarine.com/salt-away-sa ... JJr_D_BwEI I have used this mixing unit but mostly use the 100 gallon tank filled with water only and let the motors run for 20 minutes.
 
You might consider using a flush bag. It’s a bit more time consuming, but the engine is doing the circulation work without additional pressure from the hose. I don’t recall who made mine, but can dig it out if needed
 
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