Honda bfp15d4 overheat

[GR BLU]

The outboard keeps tripping the overhead alarm/shutoff after several minutes. Cooling indicator is flowing, it's not upper or lower oil, and I replaced the thermostat. What do I check next? Thanks.
Jerry

 

[Scott Danforth]

Salt water motor?

 

[GR BLU]

No, freshwater, but pretty murky lake.

 

[MattFL]

When was the last time the pump impeller was replaced?

 

[GR BLU]

Never, but could that be it if the indicator is flowing?

 

[flashback]

Never, but could that be it if the indicator is flowing?

Sure could,, how old is engine..

 

[GR BLU]

Engine is a 2004. I am the second or maybe third owner, so I have no idea on the hours. You are suggesting I check the impeller next? I can try to do that.

 

[flashback]

Your over due for a new impeller.

 

[MattFL]

Engine is a 2004. I am the second or maybe third owner, so I have no idea on the hours. You are suggesting I check the impeller next? I can try to do that.

Yes, impellers are regular maintenance items that must be changed on a regular calendar schedule, regardless of hours used. The impeller is rubber and it works by flexing the rubber, so when the rubber gets old and stiff the pump efficiency can go down significantly, especially if bits of the impeller start to break off. If you change it yourself, pay close attention to see if there are missing pieces. If yes, make sure they are accounted for.

 

[GR BLU]

Thanks so much for the input! YouTube makes it look like this should not be too tough to switch myself.

 

[MattFL]

It's not usually difficult. Tip: when you re-assemble, smear all of the bolts with good grease, that makes it easier to disassemble next time. Especially if it's used in salt. Not knowing the history of that motor, be careful the first time you disassemble it in case any of the bolts are corroded and stuck, they can be easy to break off.

 

[GR BLU]

That was definitely a problem! I've got a new one coming from Amazon.

 

[flashback]

While you're waiting hunt down the missing fins.themostat housing is a likely place to start. They may have disintegrated and passed thu but if not you still will have problems..

 

[MattFL]

As mentioned above, do your best to find those missing pieces. Also I very strongly recommend an OEM impeller, do not go aftermarket unless you absolutely have to. Also check the wear plate (metal plate under the impeller) and the cup to make sure neither are worn badly. When you re-assemble, coat the drive shaft, wear plate and cup with good grease. There may be an o-ring on the top of the impeller housing, where the water tube inserts. On a motor that old, the o-ring might also be hard and brittle. A new one is a good idea. Also coat that oring with grease before reassembly.

 

[GR BLU]

I really appreciate all the advice. I did everything above (except getting oem part, I read that too late). At first I still had water flow issues, but then I used a flush-out adapter to clear from above, and everything seems to be working great now. If anyone has a name of a particularly "good grease" I will get some to have on hand. I got a small generic tube at Ace that said it was good for marine applications. Thanks again.

 

[MattFL]

Any name brand marine grease should be fine. Belray Waterproof Grease is great for things that you don't want to corrode, like the drive shaft, bolts, etc.. It's thick and stays put. Lucas makes a really nice marine grease for things that need lubrication like bearings, cables, the water pump cup, etc.. There are surely other good ones, these are just the ones I've personally had luck with. I'm sure whatever you used is fine.