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Water flowing out upper exhaust port help

D

Dal Monico

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"I own a Honda bf15a. I believ

"I own a Honda bf15a. I believe it is a 2000 model. Engine is running fine, not overheating. Very strange thing has started recently. Water is flowing out of the upper exhaust port below engine cowling. I'm not talking about a little spray, its like a tap flowing out.What is causing this, is it a serious problem. The flow out the telltale appears normal, although sometimes it decreases then spurts a bit. I have only run the engine in a tank for brief periods since noticing this. Is running the engine going to cause damage with this occurring. I have talked to a couple of Honda mechanics and none of them had heard of this before. Does anyone know the cause, and can it be repaired by do it yourself means. Please help, I'm going on holidays soon and all the shops are backed up with jobs already waiting to be done."
 
"Dal, have never heard of this

"Dal, have never heard of this either, and will do a little guessing here.

The exhaust housing (leg) "normally" fills with water around the exhaust tube (or inner housing depending on design).

This is done by design to help cool the exhaust and act as a "muffler". Normally however, the water will exit through the lower end along with the exhaust.

From what you describe I'm wondering if you have some sort of blockage in the lower end of the exhaust housing which is forcing the water to exit where it can (the exhaust holes high on the leg).

Would be difficult to confirm without dropping the lower unit, but you may just want to try running your garden hose through the prop (thru-hub exhaust) at as strong a pressure as you can manage and see if any "gunk" comes out..."
 
"Hi, Graham.

Thanks ever so

"Hi, Graham.

Thanks ever so much for the reply. Could you clarify a little for me. Do you mean, remove the prop and try to force the hose pressure up the exhaust port housed behind the prop. Or, are you talking about trying to force as much water through the lower water intake ports with a set of muffs and hose tunned on full force.

I'm only mildly competent when it comes to monkey wrenching on 4 stroke outboards. Is there a possibility that doing what you suggest might force water into the cylinders through an open exhaust valve. Thought I'd ask so that I didn't cause more problems, just to be safe.

By the way I have checked the plugs more than a few times to make sure no water was entering the cylinders while running. The engine temperature while running was no higher than 140-165 degrees. The engine was only was only run in the tank for short periods with medium revs to obtain temp. It seems that less water comes out the upper exhaust port when the muffs are used, rather than when run in the tank.

Any further suggestions would be greatly appreciated, thanks again."
 
"Hi Dal, I'm not talking a

"Hi Dal, I'm not talking about the water intakes here. And your tempurature sounds good so wouldn't suspect a problem in that area.

All I am suggesting is: you can leave the prop on and just blast some hose water right into (hole) in the middle of the prop. This is where the exhaust exits (mostly) plus any unburnt/burnt oil (goop) that has come out of the engine exhaust.

It's possible (but I'm not sure) that something has partially blocked off the (channel) between your exhaust housing and the (feed) for the prop exhaust. This would "maybe" explain why the water is exiting so high up on the leg (just looking for a way to get out).

Spraying water in here won't hurt anything, it's usually underwater anyhow...

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"Graham, thanks for the reply

"Graham, thanks for the reply with the detailed pic. Gave it a try no luck. The motor had sat all winter and developed this problem when I restarted it recently. I haven't taken the motor out since because I was afraid to cause any further problems. Do you think that it would be wise to take it out for a run and see if that blows the crud out. Any further suggestions would be greatly appreciated."
 
"Dal, I don't think that t

"Dal, I don't think that the water exiting at that point is really causing any harm. I just can't think of anything that it would "bother".

If the blockage was too severe the motor probably wouldn't run well, if at all, because the exhaust wouldn't exit - create too much pressure and it would stall out on you.

Give it a try - keep an eye on it - and see what happens. It is an odd (problem) if you can even call it a problem.."
 
"Graham,thanks for your reply.

"Graham,thanks for your reply. I guess I'll take it out for a run and see what happens. I'm just paranoid to run it with such a strange thing happening. The last thing I want to do is cause damage to the powerhead. I appreciate your suggestions, thanks again."
 
Well I used the motor through

Well I used the motor through my holidays and into October. Engine ran flawlessly. I guess the water coming out the upper exhaust port wasn't a serious issue as you said . Thanks for your advice Graham.
 
"I HAVE JUST BOUGHT A PONTOON

"I HAVE JUST BOUGHT A PONTOON AT A VERY DECENT PRICE/GOOD DEAL BUT NOW WONDER IF SO. 2003 40HP HONDA AND I DON'T SEE IT PEEING OUT THE BACK ANYWHERE LIKE MY OLD YAMAHA USED TO, ANY THOUGHTS--IT DOES NOT OVERHEAT AT ALL"
 
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