outboard (Honda BF50A) overheating 1st day out

[DaveC426913]

Help!

So I launched my SeaSaw today. This is only my second season with SeaSaw.

I'd had the motor professionally winterized last year. I pulled off 2 pieces of tape over the prop (one over the end, the other around the prop's neck). There were no other tapes.

Motor worked fine until I throttled it up, then the overheat alarm started screaming. The engine got very hot. (I hope I haven't permanently damaged it.)

So now I can't figure out what's wrong. Apparently, it should be "piddling" water from the "nape-of-the-neck" (you can tell I'm not a mechanic), which it isn't.

My mentor and my Googling seems to point to a failed impellor, which if true, I will repair. (I don't know when the impellor was last serviced).

What I want to know is this: should I confirm the problem, or look for other solutions, before getting a new part and replacing it?


Dave

[Catigale]

No pee stream = bad impeller 99.9% of time. Only other cause is a plugged hole which is usually visible.

[Fxwg80hd]

No pee stream = bad impeller 99.9% of time. Only other cause is a plugged hole which is usually visible.

Catigale is right. One thing that has to be done when replacing the impeller is to flush the motor at the same time. I had my impeller replaced, but the pee stream would stop after a while. At first I thought it was wasp building a nest over the pee stream port. I would work on it for a while and a piece of the old impeller would pop out and the pee stream would start again. After about another days use same problem. Finally I flushed the whole motor really good and have not had a problem since.

Most mechanics are lazy and will only replace the impeller without flushing the motor (either that or they want to insure return business), so the customer will have to tell them to do that. Not sure why mechanics do this since everyone of them knows there little bits of the old impeller inside the cooling passages.

[rwmiller56]

To be on the conservative side, I replace the impeller every 2 years.

[opie]

Once you replace your impeller, if your BF50A is pre-2004, you should upgrade to a larger indicator joint.

See these links https://sites.google.com/site/bf50impellernotes/

http://www.macgregorsailors.com/forum/v ... =indicator

[DaveC426913]

Thanks guys. I'll replace the impellor.

Question: I did not heed the warning at first to shut off my engine. I did throttle it back until the siren went off, and took the cowling off, but I ran the engine for a least 10 minutes after that at dead slow.
How likely is it that I've damaged my motor?

[Catigale]

Live free from worry

I 'flushed my Mercury' for 15 minutes with a Garden hose attached to the fitting, wondering why I had no water coming from the exhaust, assuming the thermostat wasn't open...turn out I twisted the pipe while I was screwing the hose on, and it was kinked and blocked

Upshot was I ran the motor at idle for 15 minutes with no water.

7 years later I'm still on the same impeller with good water pressure.

[Tomfoolery]

Did you get the tape out from under the ventilation plate? There are cooling water inlets on the sides of the lower unit, and under the ventilation plate.

Also, that pee hole clogs particularly easily on the Hondas, according to the mechanic that surveyed the engine before I bought the boat. I splashed it in the canal once, got just a dribble, pulled the boat, and discovered (at home) that a piece of crud was mostly blocking it. Nothing else wrong, just some crud. Wiped out the day for me.

But if the alarm is going off, I'd be more inclined to think bad impeller, and/or tape over the other inlets.

Ah, I see from the links above that my mechanic was right - the engine fitting is a bit undersized on the older ones. A clogged pee hole can be fixed with a paper clip, but the engine fitting and hose needs to be updated. A rainy day project.

[DaveC426913]

Good news: Impellor is a very easy fix - even with little experience. Took me two leisurely hours, in a dinghy lashed to the transom.
Bad news: didn`t fix the problem. Still no peeing. Still overheating.

My next guess:
1) the old impellor disintegrated and is blocking the flow.
2) I`ve installed the new impellor wrong and it isn`t turning.

I`ll try flushing it. How does one do that... Is there an inlet pipe somewhere on the outside
(EDIT: Seems like the hose inlet is under the cowl.)

Other ideas welcome.

[DaveC426913]

Did you get the tape out from under the ventilation plate? There are cooling water inlets on the sides of the lower unit, and under the ventilation plate.

I`ve looked and looked. No other bits of tape.

There are two inlets on either side of the lower unit, below the ventilation plate, but no other inlets.

[06HARLEYULTRA]

Sent you a PM.

Rich

[DaveC426913]

Sent you a PM.

Rich

Got it thx.

[DaveC426913]

OK, I`ve got a question (which I guess I need an answer to by about 10AM). I`m reading up on flushing the cooling system and I keep reading about people complaining that the water is coming out cool, meaning the thermostat hasn`t opened.

I guess that means I ought to be *running* the engine while flushing it...

[Tomfoolery]

Did you get the tape out from under the ventilation plate? There are cooling water inlets on the sides of the lower unit, and under the ventilation plate.

I`ve looked and looked. No other bits of tape.

There are two inlets on either side of the lower unit, below the ventilation plate, but no other inlets.

Mine has a third one, actually in the ventilation plate, facing down toward the prop, FWIW.

Bits and pieces coming off an old impeller is something I've heard of but never experienced, as change them too often for that to happen. A keelboat that I used to own, with a Yanmar diesel, had an impeller that was hanging on by a thread in many places, so I get kinda paranoid about keeping them no more than 2 years old. Too hard to get the pieces out of the passages once it comes apart, which may be what happened to yours.

[DaveC426913]

. Too hard to get the pieces out of the passages once it comes apart, which may be what happened to yours.

So how *do* you get them out?