Cooling system blocked?

[Jerry Maras]

I've got a 200 hp Mariner and replaced the water pump as a precaution. When I started it up, there was no tell tale, and the warning horn was going off. I checked both t-stats and they're fine, no blockage in any visible hosing. I removed the lower unit and tried to force water from a garden hose up through the water tube, and most of it fell straight down from the power head.

Other circumstances caused me to put a newer lower unit on, and I hoped that it might resolve my water issues, (although I didn't replace the pump in this one thinking I may have screwed up the old one). Not so. The same problem exists. The motor runs fine, 120 compression on 5 cyl, one at 115. After a minute or so of no water, I shut it down.

I've also tried leaving the t-stats unmounted to see if any water would come out, and it didn't.

I might add, the water pressure gauge reads zero.

Any ideas where this blockage might be or is it possible that there is an internal leak?

 

[andy6374]

Re: Cooling system blocked?

Did you make sure you installed the impeller key? Is the water tube properly inserted into the waterpump housing?

Just asking. I've done both, it's easy to do stupid things.

 

[Jerry Maras]

Re: Cooling system blocked?

Well, the first lower unit I'm sure the key was in place, the second unit I'm assuming it is because I didn't rip the water pump apart before installing it. I doubt that the pump is the problem because as I said, I couldn't force water through with a garden hose.

Interesting question on the placement of the water tube though. Unfortunately when installing the tube, your kind of blind and can't see where you're putting it. Kind of like making love under the covers without any lights if you know what I mean. My first try on the old unit I actually did have a problem where it wasn't seated very well. After I removed the lower I saw there was too much slop and was able to seat it better. I have been trying to find a good illustration so I know what I'm actually looking at. My Clymer's manual is pretty much useless for tracking the water flow. Under the garden hose to the water tube, the water did come right out the drive shaft housing. Do you think there might be a way to falsely seat the water tube to the block?

 

[bamspringtx]

Re: Cooling system blocked?

Is it a optimax? efi? xr6?

 

[Jerry Maras]

Re: Cooling system blocked?

[1980 200 hp V-6 Mariner

 

[andy6374]

Re: Cooling system blocked?

Your watertube isn't permanently connected to the bottom of the block?

Usually you have to align the watertube with the housing.

 

[Jerry Maras]

Re: Cooling system blocked?

Now that you mention it, I guess it was connected but it was real sloppy then I tapped it in to stabilize it figuring it had just loosened from pulling off the lower. I have Clymer's manual and I just picked up a Seloc manual and I can't find any detail on how that tube is actually connected to the block.