Overheating

[NYBo]

I started my brand new Honda 50. I first tried on muffs. Nothing from the telltale and the overheating alarm sounded after a couple of minutes. Then I tried on the muffs with the lower unit submerged in a large Rubbermaid bin. Same thing. Then tried in the bin without the muffs and with water running into the bin. Same result. I contacted my dealer, who talked to the service tech who mounted the motor, who told him Hondas can't be run in a bin because they will suck in the exhaust and no water. Anyone ever hear of such a thing? They also screwed up the electrical system so the boat goes back regardless.

 

[ahicks]

The Honda 40/50's are kinda unique in that there is a water pick up located directly above the prop. Unless that port is covered/taped shut, it takes a lot of water volume/pressure on the muffs to be able to run without burning up the impeller, and then you can only run it at an idle. Anything higher than an idle, and even with a lot of pressure/volume, that extra inlet is going to suck enough air to smoke the impeller. Sure, if you could seal that inlet things would be different, but I've never had much luck doing that.

No clue what your bin looks like, but if it were not big/deep enough to hold a water level well above where the pump is located, it would be too small. I use a cut down trash can with the cut placed as high as possible.

So 2 strikes against you the way I see it. Inadequate water flow on muffs, and questionable water level while running in the bin. If the bin is deep enough, there is no issue mixing exhaust and water intake. I've been messing with this engine for a while now, and you could never prove that idea by me....

My first step in trouble shooting would be to inspect the impeller. If it's smoked, suggest you install a complete kit.

 

[NYBo]

The Honda 40/50's are kinda unique in that there is a water pick up located directly above the prop. Unless that port is covered/taped shut, it takes a lot of water volume/pressure on the muffs to be able to run without burning up the impeller, and then you can only run it at an idle. Anything higher than an idle, and even with a lot of pressure/volume, that extra inlet is going to suck enough air to smoke the impeller. Sure, if you could seal that inlet things would be different, but I've never had much luck doing that.

No clue what your bin looks like, but if it were not big/deep enough to hold a water level well above where the pump is located, it would be too small. I use a cut down trash can with the cut placed as high as possible.

So 2 strikes against you the way I see it. Inadequate water flow on muffs, and questionable water level while running in the bin. If the bin is deep enough, there is no issue mixing exhaust and water intake. I've been messing with this engine for a while now, and you could never prove that idea by me....

My first step in trouble shooting would be to inspect the impeller. If it's smoked, suggest you install a complete kit.

The bin was deep enough to cover to cover all the intakes, over the top of the anticavitation plate and then some. I also never took it above idle.

 

[Sea Rider]

Could it be the overheating alarm's sensor triggering prematurely due to being faulty ? For how long did the motor was tested on such bin when the overheat alarm went on ? The issue is that you can't possibly cool any motor with heated water recirculating inside the bin. The bin, barrel needs fresh water comming in, heated water going out for motor to cool properly..

Happy Boating

 

[NYBo]

Could it be the overheating alarm's sensor triggering prematurely due to being faulty ? For how long did the motor was tested on such bin when the overheat alarm went on ? The issue is that you can't possibly cool any motor with heated water recirculating inside the bin. The bin, barrel needs fresh water comming in, heated water going out for motor to cool properly..

Happy Boating

The motor had 0.0 hours on the clock. Cold water from the garden hose was running constantly in the bin. I only ran the motor for about two minutes each time and shut it off immediately when the alarm sounded. I guess the screwy additional water intake above the prop was the the problem but there is nothing in the owner's manual about any cautions when running the motor on land.

The boat is back at the dealer.

 

[Sea Rider]

There is nothing in the owner's manual about any cautions when running the motor on land. The boat is back at the dealer.

Most Owner's Manual states very poor indications regarding testing or flushing any motor on dry land whether using a flushing adapter, bins, barrels or muffs, it's up to you to find the best method to flush with fresh water your beloved motor...

Happy Boating​

 

[MattFL]

I've got a 50HP Honda I bought new in 99' and have run it on muffs after every use, and in a garbage can several times, no problems at all. If on muffs you have to be sure there is enough water flowing that it's also coming out the vent that is under the anti ventilation plate. In the bucket it needs to be above the water pump, the higher the better. But now that it has been run for many minutes (total) without water in the pump, your pump might be cooked and need replacing. You cannot run outboard pumps dry, they will overheat and melt parts. Assuming that part of the motor hasn't changed much, the water pump on that motor is super easy to replace.

Side note: cavitation and ventilation are entirely different. Cavitation happens when the pressure on the low pressure side of the prop drops so low that the water boils, leaving bubbles that will collapse and erode your prop. Ventilation is when air from above gets mixed up in the water around the prop. The plate is to prevent ventilation.