50HP Mariner cooling poblem

[Tex60]

This is probably going to be simple I'm sure that someone has seen this before, 50hp 3cyl Mariner, new impeller, checked all passage ways with air and water to make sure nothing is blocked. water is going in and comming out the exhaust but not comming out the pee tube. checked the hose from the top of the head not blocked put water in to the top of the head where the pee tube connects and it runs out the bottom with the lower unit off put water in through the copper tube that goes up from the pump with a water hose and it comes back out the exhaust but will not come out the pee tube. In the service manual I can't find this problem addressed and it appears that this engine has no thermostat. BTW engine has 120psi compression on all 3 cyl.

Based on my experience with other types of engines I would say busted gasket somewhere but I don't want to tear into the whole engine when I just got this thing running again with a fuel system rebuild.

Any help would be appreciated.

 

[Fishing Dude too]

Re: 50HP Mariner cooling poblem

bad impeller

 

[jeffersondodson561]

Re: 50HP Mariner cooling poblem

Everything seems normal with water exiting the exhaust, tell tail (pee tube) is probably blocked. This is just to tell the operator that the engine has water pressure and does not contribute to the exiting water flow. Most of the water exits the prop/gearcase area (exhaust).

 

[Tex60]

Re: 50HP Mariner cooling poblem

The Impeller is NEW and pumping water up into the head unit, the pee tube is NOT BLOCKED because I put water in through the pee tube with no obstructions. And it's not normal because water for some reason is going out the exhaust with out getting to the top of the head and it is getting hot.

 

[Fun Times]

Re:Just another opinion for you to take a look at is all.

Re:Just another opinion for you to take a look at is all.

It is possible that you might have a water leak in the tube area that is bringing the water up from the lower unit. The only way to find out is to drop the lower unit and yank the tube out for inspection.

Also under the power head where water tube connects, There may be a round bakelite looking ring with some seals and gaskets in the area as well. When these engine over heat, There is a chance that it could melt part of this ring, closing off part of the hole. You could still get some water out tale tail but it should be some pretty hot water if it's blocked up.

Would need your serial number for verification, But for example, take a look at numbers 24 thru 27 (along with 21 Maybe).
http://www.mercruiserparts.com/Show...nbr=120&bdesc=SHIFT+LINKAGE+AND+EXHAUST+PLATE

 

[Tex60]

Re: Just another opinion for you to take a look at is all.

Re: Just another opinion for you to take a look at is all.

edited:


this one is still a mystery but it is now working...........I took the lower unit off again dissasimbled the pump nothing was out of place, new impeller was still looking like it came out of the package, key way in place, gaskets etc..........I then reassembled everything and put it back on and it worked?!?!?!?! I don't know what was out of place, miss fitted but something was just not right enough for it not to pump properly. I joked and told my dad that it was simply that I hadn't taken it apart and put it back together the correct number of times. :facepalm:

 

[jeffersondodson561]

Re: Just another opinion for you to take a look at is all.

Re: Just another opinion for you to take a look at is all.

Gremlins!