Johnson lower unit identification - is there a part number stamped somewhere?

osuchica1284

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Aug 21, 2017
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I have 2 lower units - one is seized and was off the boat when I bought it, the other is on the boat. I THINK the one on the boat is the original to that motor but I want to be sure - both lower units are about the same dimensions and near as I can tell (based on sterndrive.info) both are large v6 gearcases compatible with my 1989 200hp vro, 25" but I want to be sure. The main differences are a broad cavitation plate vs thin and 2 slots above the cavitation plate vs 6 holes. It also looks like the thin cavitation plate has holes for zincs whereas the broad cav plate does not.

shop2.evinrude.com parts breakdown shows my model motor having a lower unit with 2 slots above the cav plate

Is there any way I can tell what they are without tearing them apart and cross checking the part numbers of the internals? Thanks!
 

Faztbullet

Supreme Mariner
Joined
Mar 2, 2008
Messages
15,590
Measure shaft OD at rear seal and look and see if it has the 2 tabs to hold carrier in vs the 4 bolts.... Shaft sizes 1-3/16 used on pre 1990 motor and 1-1/4 used on 1991 and up. A early unit hydro will have a different type shift rod. 1980 and up unit will interchange put gotta measure the driveshaft and spline length going into powerhead
 

osuchica1284

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Joined
Aug 21, 2017
Messages
26
Ok thanks ... but is there a part number to be found on the housing so I can find out exactly what year / model they are from?

And while I'm on the subject, the tip of the skeg is bent on the lower unit I think belongs to the motor - am I limited to exact year matches when it comes to swapping parts into different housings that are the same type? (Type "O") Or are they pretty interchangeable?
 

Faztbullet

Supreme Mariner
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Mar 2, 2008
Messages
15,590
Why are you wanting to swap parts??? Just have skeg fixed, All the parts will interchange but you have to be carefully as the tab vs bolt in carrier housings are different in carrier,reverse gear and propshaft. Also never use a used V-6 housing untill it has been checked with a alignment tool(dealer) or about $900 if you want to have around shop. I have thrown away housings that look brand new but alignment was off. This is why some unint after a rebuild chit the gears again as housing throws them off.

http://www.everythingoutboards.com/brp/2001sb/2004-09s.html
 
Last edited:

osuchica1284

Cadet
Joined
Aug 21, 2017
Messages
26
Why are you wanting to swap parts??? Just have skeg fixed, All the parts will interchange but you have to be carefully as the tab vs bolt in carrier housings are different in carrier,reverse gear and propshaft. Also never use a used V-6 housing untill it has been checked with a alignment tool(dealer) or about $900 if you want to have around shop. I have thrown away housings that look brand new but alignment was off. This is why some unint after a rebuild chit the gears again as housing throws them off.

http://www.everythingoutboards.com/brp/2001sb/2004-09s.html

WOW - great advice, thank you!

I'm a little iffy on getting the skeg repaired on account I don't have anyone (pro or hobbyist) that I trust to do it right without causing damage to the housing vs cost. I mean, I can buy a brand new aftermarket lower unit for $900 so why spend $150-$200 for a skeg repair when I still don't know how good the internals of the lower unit is? I bought this boat for a steal, in rough shape, without testing so I have no idea what nasty little secrets it holds.

But I had no idea there's such a thing as an alignment tool so thank you!
 
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