25hp slows down after 5 minutes - water pours from exhaust?

[febod]

Just got boat back from repair shop.

I had overheating issues with S.L.O.W. kicking in. The shop replace waterpump, thermostat, and temp sensor.

When out in the water I noticed the motor running significantly quieter (it may very well be the quietest motor ever) and water pouring, like a hose out the exhuast outlet.

When running at full throttle - about 20 mph, after 5 minutes it begins to slow to 19, then 18, another minute 17, etc. It never seems to go slower then 15.



I know water out the exhuast is ok, but normally I see a spray, this is pouring. Does that sound ok?

On the loss of power at full throttle. Any ideas? I am not noticing any misses, just slows down like its not getting enough gas. Tried pumping the bulb, no help.

Thanks in advance for any insight.

 

[fireman57]

Re: 25hp slows down after 5 minutes - water pours from exhaust?

Welcome to iboats. When it slows, with your cover off, see if someone can hold their fingers on the flat top of the head for five or six seconds without getting the snot burned out of them. If they can then it is not overheating. As for the bogging down when it does this try hitting the choke or the primer for just a sec and see if it speeds up. If it does then rebuild you carbs. It is an easy job with a manual. The cost of the manual will be save by one hour of shop labor rates.

 

[clemsonfor]

Re: 25hp slows down after 5 minutes - water pours from exhaust?

the new amount of water could be more than you are use to b/c your old impellor was junk and not pumping enough water and now it is.

-nate

 

[Solittle]

Re: 25hp slows down after 5 minutes - water pours from exhaust?

Be sure that you confirm that the engine is coolong properly as fireman points out. Your symptoms could be a seriously overheating engine.

 

[papasage]

Re: 25hp slows down after 5 minutes - water pours from exhaust?

coli could be breaking down . it will run alright after cooling for a few minutes for a short distance

 

[febod]

Re: 25hp slows down after 5 minutes - water pours from exhaust?

Thanks for all the responses.

I took it out last night to help diagnose it better and for sure it is overheating.

I could touch the engine block or even the big fly wheel for only about 1 second. I ran it for a while, 20 minutes at full throttle, first it slowed and then the S.L.O.W. kicked in and anything over 7 mph was causing it stall.

I am thinking that the cooling system may be blocked up somehow. Before, the exhaust outlets just under the top part of the engine would kind of spray water out with the exhuast gases. But now when I get going, 1/4 throttle on up, it is like a hose and the water is running out. Pee hole water is fine, spraying out nicely.

The reason I took it into the shop was the SLOW indicator was stuck on. The shop replaced the waterpump and the temp switch. I am guessing the temp switch is why the SLOW was stuck on.

The underlying issue that started my overheating is still unknown.

The only other tidbit of info is that my prop is not perfect right now. Around the same time problems started i hit a rock and one of the blades is bent a little, (you have to look close).

Thanks again (I am still reading, this site is great)

 

[febod]

Re: 25hp slows down after 5 minutes - water pours from exhaust?

I failed to mention its a 1994

 

[jtexas]

Re: 25hp slows down after 5 minutes - water pours from exhaust?

I don't think water should be pouring out your exhaust relief ports in the way you're describing. Is it hot or cool water? If it's cool then you know it hasn't been through the powerhead. Didn't the shop tank test the motor after the repair? Did they do a compression test? I'd do one now anyway. Originally might have been overheating due to water pump and/or thermostat; now could be a different reason - could be related to the water pouring out the relief ports. I wouldn't run it anymore it's resolved. And I'd familiarize myself with the water flow path before going back to see the mechanic. Not that I wouldn't trust him or anything...

 

[febod]

Re: 25hp slows down after 5 minutes - water pours from exhaust?

Thanks, got ears on it in the driveway right now. The water coming out of the exhaust relief port is warm. The water coming out of the pee hole feels cool, little hole above the propellor - warm, below is cool. It tough to feel what is going on with the prop water, the ears got water spraying all over the place.

After about 10 minutes the heads are burning hot, fails the 5 seconds touch test in 1 second.

I don't have a compression tester but it runs good up until it gets so damn hot. I did check the plugs and they look fine, they are not shiny clean..

Thanks

 

[fireman57]

Re: 25hp slows down after 5 minutes - water pours from exhaust?

Like jtexas said you have a blockage somewhere. One of the usual spots is behind the thermostat. Yours might not be opening enough. Pull it and when it is cool drop it in a pan of HOT water. you will see it open if it is good. I had a blockage in my '83 50hp that was blue RV sealant. Had to flush numerous times and run without tstat for a trip to get it all out.

 

[febod]

Re: 25hp slows down after 5 minutes - water pours from exhaust?

Thanks for all the feedback. Dropped it back off at the shop, I will post back when I find out what it is for everyones reference.

 

[febod]

Re: 25hp slows down after 5 minutes - water pours from exhaust?

Shop called, said pick it up.

They pulled head, and replaced water deflectors. Said they were messed up.

I will let you know after my test ride tonight.
So far, new temperature sensor, water pump, and thermostat.

Now it should be a new head gasket and water deflectors, plus everything cleaned out.

 

[febod]

Re: 25hp slows down after 5 minutes - water pours from exhaust?

Mystery solved. Runs great. Now the water that occasionally spurts out the exhaust relief is nice and hot. And I can now keep my hand on the head for 5 seconds without burning the daylights out of it.

The water deflector on the bottom was causing the water to go right back out the exhaust and relief without cooling the head.

[attachment=img=c:\boat.jpg]

 

[febod]

Re: 25hp slows down after 5 minutes - water pours from exhaust?

here is the picture, sorry about the last post

 

[febod]

Re: 25hp slows down after 5 minutes - water pours from exhaust?

Last time and then I give up. If it doesn't show up, you would get the idea, its all broken up and looks like dryrotted.

[attachment=img=boat.jpg]

 

[febod]

Re: 25hp slows down after 5 minutes - water pours from exhaust?

I am determined, hows this

http://i92.photobucket.com/albums/l29/febod/boat.jpg

thanks

 

[jtexas]

Re: 25hp slows down after 5 minutes - water pours from exhaust?

To get your pics in your reply, put "[/img]" after ".jpg" and "" before "http:" (with brackets but without quotes)

thanks for letting us know the results.