mercruiser upperunit replacement

[mattyjivs]

I have a 1985 mercruiser 470/120hp with a bad upperunit,my question is,will a 1983 470/120hp upperunit work? the #'s on mine are 1.98 gear and A301171. I asked the guy who has the 83 upper what the #'s were on his and he said 122b9003 were the only #'s on the part. He wasn't sure if the part would fit or not. Any help would be appreciated,I am new to boating and this is my first,i dont have alot to spend on repairs so am trying to find good used parts,thanx

 

[Don S]

Re: mercruiser upperunit replacement

What happened to the upper unit? if the gears went out, there will be metal particles in the lower also. Which means you need both the upper and lower.

 

[mattyjivs]

Re: mercruiser upperunit replacement

i just purchased this boat 2 days ago,the guy i bought from,assured me that the engine and lower are fine,he thinks the gear oil leaked out and seized the gears,i took his word for it,i'm not so sure it was a good idea now

 

[Bondo]

Re: mercruiser upperunit replacement

Your description of your power is Also quite Confusing,......

If you have the 470 motor,+ I Hope you Don't,......
It's rated Higher than 120hp,+ uses a 1.84/1 Gear Ratio(or there abouts)

If you have a 120hp, it's a 153cid Chevy motor,+ Does use the 1.98/1 Gear Ratio......

And,......
As Don says,.....
If the Upper Unit Puked, whether from lack of Oil, or Whatever,.....
All the metal Grindings have contaminated the Lower Unit,......
It'll Atleast need to be Rebuilt to See just how Bad it is.......

 

[mattyjivs]

Re: mercruiser upperunit replacement

i know the engine is a small 4 cylinder,i dont know why they call it a 470,as i said i am new to this,i'm just trying to figure out what i got myself into,i only paid $685 for boat motor and trailer and was told this was a good deal as long as the motor does run

 

[Haut Medoc]

Re: mercruiser upperunit replacement

120 & 470 are both 4 cylinders.......
Where are you getting the #'s from?
Do you have the engine serial #........​

 

[mattyjivs]

Re: mercruiser upperunit replacement

i talked to a guy at a local marina,he said he could replace my upper with a rebuilt one,put it on and test it for 450,i didnt ask what a lower would cost also as that was before i discovered this site,i suppose i better have both done to be safe,does anyone know if the 83 upper will fit my 85,i have a line on a good used one,thanks

 

[mattyjivs]

Re: mercruiser upperunit replacement

give me a minute and i will go outside and look at engine #'s

 

[Haut Medoc]

Re: mercruiser upperunit replacement

You need to figure out what engine you have to get the correct answer....​

 

[mattyjivs]

Re: mercruiser upperunit replacement

engine# A338806
transom assembley A326123

 

[mattyjivs]

Re: mercruiser upperunit replacement

the outdrive has a 4 on top and says 2.5L under that,im assuming its a 2.5L
4 cylinder,i just would like to get her going so i can take my kids on the water and feel confident about it

 

[Don S]

Re: mercruiser upperunit replacement

The engine serial number is for a 120/2.5L engine. You're lucky, you DO NOT have a 470.

 

[Bondo]

Re: mercruiser upperunit replacement

You're lucky, you DO NOT have a 470.

Ayuh.....................

 

[mattyjivs]

Re: mercruiser upperunit replacement

no ideas if 83 will work with 85

 

[Haut Medoc]

Re: mercruiser upperunit replacement

It should, just make sure the gears are 2:1......​