To Hot To Run

garyr

Recruit
Joined
Aug 23, 2009
Messages
5
Hi ,my son and I purchase a 1987 Capri Bayliner , four cylinder 140 hp, G.M. motor 20.5 ft, . This is our first i/o boat .Last year we had the boat out maybe 12 time?s , it run perfect. The heat gage went up very little ( below 100 % ) the gage will read as high as 250 % . The trouble started this spring when after a long cold winter I decided to start it up in the driveway. I had a 45 gallon plastic barrel, which I cut in half and filled with water, put my cobra outdrive in it and started up the motor, I ran it 3or 4 minutes and shut it off , it ran good. We then took it to the lake and it was running great, took it up to 30 mph. for about 5 min. and all of a sudden the motor started making a dieseling noise and stopped running ? Smoke was coming out of the motor cover as if it was on fire. My son was driving the boat and nether him or I was watching the heat gage which was as hot as it could get. Well I thought the motor was cooked. So we let the motor cool off and tried to start it a couple of hours later and believe it or not it fired up, it ran a little rough but it ran, Now a month has past and I bought a manual for the boat. I now know my trouble started in the barrel of water ( I?LL NEVER DO THAT AGAIN ) I got all the piece?s of impeller out the water intake by taping off one side of the screened inlet and putting the water muff?s on the other side and then sucking with my shopvac at the impeller canal it worked great. I now took the thermostat housing off and found two big piece?s blocking the inlet. I put a new impeller in and took it for a ride, it ran pretty good and still seemed to have a lot power, but at 30mph the heat gage is at 175% and if you go slow the heat gage will go right up to 200% even 225% , so this is where we are at right now. Also I did not mention that there was no thermostat in it and there?s still not ,ihave not taken the inlet hose off at the thermostat yet while running the motor.
it will be my next step . P/S If you have any idea?s of what else to check I sure would appreciate your help. gwr
 

jtybt

Senior Chief Petty Officer
Joined
Aug 5, 2009
Messages
730
Re: To Hot To Run

I think you should get a service manual and start reading up on I/O's. Not to be harsh, but, your problem is basically, you don't know what you're doing.

There's nothing wrong with running with the drive in a barrel of water. In fact, that's a preferred method with a water hose also on.
 

myoldboat2

Petty Officer 1st Class
Joined
Jun 3, 2007
Messages
300
Re: To Hot To Run

I think you may have a piece of impeller blocking part of the raw water cooling circuit. If it was me, I would divide and conquer. I would check the water flow from the raw water hose that connects to the back of the thermostat housing. That would tell you if you have good flow to the engine. I suspect the problem is in the sterndrive. Either you put the impeller in wrong and trashed it, or a piece of the old impeller is up inside the water circuit blocking it. I have an older stern drive, a 1974 late model I, and I had impeller pieces in the water pocket that would sometimes block the flow.

Also, your engine got really hot. If it was me, I'd do a compression test and have somebody check the head.

But just because I'd do something doesn't mean the experts would...
 

garyr

Recruit
Joined
Aug 23, 2009
Messages
5
Re: To Hot To Run

I think you should get a service manual and start reading up on I/O's. Not to be harsh, but, your problem is basically, you don't know what you're doing.

There's nothing wrong with running with the drive in a barrel of water. In fact, that's a preferred method with a water hose also on.

Thank-you for your input, i am learning about this boat. As the old saying go's ,YOU 'VE GOT TO PAY TO LEARN .The omc dealer here told me that there is no way that the raw water pump will pull the water up to the motor from the barrel of water ,he said that when i run the motor in that barrel of water that i burned the impeller out in seconds.
 

meesh

Petty Officer 1st Class
Joined
Aug 24, 2008
Messages
256
Re: To Hot To Run

After checking the problems mentioned above, if you still have the problem you may want to consider changing your raw water pump. Sometime just changing just the impeller is'nt enough. You may have a distoted housing.
 

jtybt

Senior Chief Petty Officer
Joined
Aug 5, 2009
Messages
730
Re: To Hot To Run

Sorry garg,

Maybe I should have elaborated a bit more. The barrel should filled with water high enough to completely submerge the drive leg.
 

forgedin78

Seaman
Joined
Aug 2, 2009
Messages
50
Re: To Hot To Run

Thank-you for your input, i am learning about this boat. As the old saying go's ,YOU 'VE GOT TO PAY TO LEARN .The omc dealer here told me that there is no way that the raw water pump will pull the water up to the motor from the barrel of water ,he said that when i run the motor in that barrel of water that i burned the impeller out in seconds.

If you have the water up above the water inlets, why wouldn't the impeller push the water up? Its just like being in the lake right?
 

SPOONMAN1

Petty Officer 2nd Class
Joined
Aug 19, 2008
Messages
177
Re: To Hot To Run

Thank-you for your input, i am learning about this boat. As the old saying go's ,YOU 'VE GOT TO PAY TO LEARN .The omc dealer here told me that there is no way that the raw water pump will pull the water up to the motor from the barrel of water ,he said that when i run the motor in that barrel of water that i burned the impeller out in seconds.

OMC no longer has dealers and if the outdrive is in a barrel of water or an ocean the impeller should pull the the water up. (so long as the inlet holes are submerged)
 

myoldboat2

Petty Officer 1st Class
Joined
Jun 3, 2007
Messages
300
Re: To Hot To Run

> The omc dealer here told me that there is no way that the raw water pump will pull the water up to the motor from the barrel of water ,he said that when i run the motor in that barrel of water that i burned the impeller out in seconds.

huh??

Not following that. Is he saying that putting the drive in gear will throw all the water out of the barrel?

C'mon, as long as the intakes are covered with water, the drive doesn't know it's in a barrel.
 
Top