Newb Merc Water Cooling Questions

[XavierSPL]

Hi Everyone,

After lurking for a bit I thought I'd jump in and pick some brains;

Just a little background first - I'm fairly mechanically inclined with cars, motorcycles, etc but boats are new to me and I just purchased my first one and am trying to get her ready for the water..

It's a 1990 Sea Ray 160 that I bought from a friend, with a Merc 3.0 and only 420 hours. The boat was rarely used obviously but spent a good part of the last couple years neglected and uncovered.
I'm trying to examine all the common problem areas and address any issues I find and so far have:

Replaced the battery and all battery cables
Replaced the starter with the newer style (old one was dead)
Purchased the full transom seal kit and am currently in the middle of replacing


After I changed the starter, it only took a couple turns to start her up with some new plugs and she purred beautifully. I ran it a couple times with a muff on for only about 5 mins or so each time. Oil pressure and water temp were fine.
The issue now:
Lastnight while pulling the shift cable I noticed that the water hose on the front of the engine had been disconnected by someone and was tucked in a way that I just didn't notice. So, obviously the temp only showed as being ok because I only ran it for 5 minutes at a time, my concern is that no water ever came through the hose at all.. So, my question is, considering the common problems, should I assume the impeller is bad, the water pump, or both?? I don't know if it matters much but upon removal of the outdrive, the u joint bellow was full of water.

Thanks in advance for any thoughts or suggestions!

 

[XavierSPL]

Re: Newb Merc Water Cooling Questions

100+ views and no reply?? Anyone?

 

[MarkSee]

Re: Newb Merc Water Cooling Questions

Since you have no real history but at least know you may be changing the gimbal bearing and u-joints because they have been sitting in water you found in the bellows, you will want to pressure test the drive before splitting the halves.
That may lead you to other issues but examine the water pump and it's contents but would make sense to install the full rebuild kit.

Check the stickies for making a pressure tester.

Mark

 

[NHGuy]

Re: Newb Merc Water Cooling Questions

I would also do the drive pressure check, but on the other hand if you drain the drive and the oil is not milky you could wait on the pressure test.
Yes, assume the impeller is bad, also check the impeller housing because it can be damaged by exhaust heat from dry, non cooled exhaust.
With water in the bellows I'd replace it and the gimbal bearing too, and I'd do the universal joints.
The engine water pump hardly ever fails, don't just change it without reason.
Oh, and welcome. I am sure you will really enjoy boating.

 

[XavierSPL]

Re: Newb Merc Water Cooling Questions

Thanks for the tips guys, I got the new gimbal bearing in last night and regreased the u joints, i'm keeping my fingers crossed they're okay, they turn smoothly without any play. I'm heading out to the boat shop shortly to get the water impeller kit and within any luck will have the outdrive back on and the boat in the water this weekend. (I'll fund out pretty quickly about the u joints i'm guessing).
In Nashua here NHguy!

 

[ktbarrentine]

Re: Newb Merc Water Cooling Questions

I would say that it is fairly risky chancing just a re-lube of u-joints that have been sitting in water for who-knows-how-long. (so, good luck with that). I would replace just on GP. And after I replace the impeller, I always pressure test, again on GP, even if the lube looked good on drain-out. Simple (and fun) to do and only takes 15 minutes. Would reveal a mispaced quad ring, at the least. I would also check for the source of water in your bellows. Based on age....(and who knows how long the bellows has been there), you're probably looking at some cracking/leaking. (I would hate to have you find out about your u-joints somewhere in the middle of the lake!)