Help identifying stern drive/bellows/transom kit. 1981 mercruiser 120

[merc120_81]

hello all,

I have a 1981 mercruiser 120 io/ the stern drive S/N is 5804180 and transom plate s/n 5776812.

1) what model sterndrive unit is it (pre alpha.. alpha r/mr etc?)

2) What transom kit (Bellows, gimble bearing, cooling hose, etc) Would I use on it?

3) would a dry rot/small leak in the hose between the transom plate and sterndrive unit (cooling water) cause highspeed overheating? idles all day no temp rise, up on plane any rpm boat overheats ( it hits 170/180 and I shut it down to an idle to cool before going anymore.


THANK YOU!

 

[Eric 3.7LX Alpha 1]

Re: Help identifying stern drive/bellows/transom kit. 1981 mercruiser 120

hello all,

I have a 1981 mercruiser 120 io/ the stern drive S/N is 5804180 and transom plate s/n 5776812.

1) what model sterndrive unit is it (pre alpha.. alpha r/mr etc?)

2) What transom kit (Bellows, gimble bearing, cooling hose, etc) Would I use on it?

3) would a dry rot/small leak in the hose between the transom plate and sterndrive unit (cooling water) cause highspeed overheating? idles all day no temp rise, up on plane any rpm boat overheats ( it hits 170/180 and I shut it down to an idle to cool before going anymore.


THANK YOU!

Here you go, see the attached chart:
Looks like it should be a MC-1

 

[merc120_81]

Re: Help identifying stern drive/bellows/transom kit. 1981 mercruiser 120

Thank you!

Would this kit, work for bellows/cooling hose/gimble bearing etc. Mercruiser
30-803097T1?

 

[Eric 3.7LX Alpha 1]

Re: Help identifying stern drive/bellows/transom kit. 1981 mercruiser 120

That should get it done for you. Might want to replace the lower shift cable too while your are in that deep.

 

[achris]

Re: Help identifying stern drive/bellows/transom kit. 1981 mercruiser 120

And since you'll have the leg off, check the water pocket cover... It's on the bottom of the upper housing. It's plastic cover in the exhaust cavity, and if it gets hot it melts and the gasket leaks, allowing exhaust gasses in when under load, causing an overheat. There's 2 way of checking it...

First way is to put a section of clear hose in the water line from the transom and watch for bubbles (under normal operating conditions, which means out on the water running normally).

The second way is to split the drive and pressure test the water cavity itself. It's not easy to plug that big hole at the front of the drive, but it can be done. Then just pressurize from the water tube and spray a bit of soapy water around the edges of the cover... See bubbles, bad news....

Chris.....

 

[merc120_81]

Re: Help identifying stern drive/bellows/transom kit. 1981 mercruiser 120

All. Found 4 chunks of old impeller stuck in the rubber hose in bell housing area.. She runs 145 150 f all day long now. Thanks all