1976-77' Evinrude 55HP Adapter plate differences , need help

DamianJP

Chief Petty Officer
Joined
Mar 25, 2008
Messages
612
Hey guys

I got a midsection from a off a 50ESL75B motor, which is a 1975 Evinrude 50HP.

I picked it up for a 1977 Evinrude 55HP powerhead.

I thought everything was a %100 but the adapter plate looks different.
The Part numbers for both the adapter plates were both 0351178 so I thought it was okay.

My old one off the 1977 55HP
Notice the hole isnt plugged up with a rubber grommet and it is on the inside of the gasket seal.
DSC01481CRICLE2.jpg



New one on mid section 1975 50HP
Notice the hole "IS" plugged up and on the outside of the gasket seal.
DSC01476CIRCLE1.jpg




Why are these two different if they have the same part number?
And most importantly what is the function of that area on each adapter plate and why is one plugged up and there other is open and leading to the power head I assume?

Reason why I want to use the adapter plate that came with the midsection is my old adapter plate had one of the exhaust tube bolts broke off and I drilled and taped new threads. The bolt screws in okay but only so deep for some reason , I can make it work with loctite but I would rather use the %100 adapter plate if possible.

Please let me know my options and the function and reason why the adapter plate are different, my thirst for knowledge is all most as strong and me wanted to get this part of my project done.


Thank You,
DamianJP
 

DamianJP

Chief Petty Officer
Joined
Mar 25, 2008
Messages
612
Re: 1976-77' Evinrude 55HP Adapter plate differences , need help

Bump
 

DamianJP

Chief Petty Officer
Joined
Mar 25, 2008
Messages
612
Re: 1976-77' Evinrude 55HP Adapter plate differences , need help

Bump
 

DamianJP

Chief Petty Officer
Joined
Mar 25, 2008
Messages
612
Re: 1976-77' Evinrude 55HP Adapter plate differences , need help

Bump
 

DamianJP

Chief Petty Officer
Joined
Mar 25, 2008
Messages
612
Re: 1976-77' Evinrude 55HP Adapter plate differences , need help

Well I just found out something...

The new superseded part number to both the 1977 55hp and the 1975 50hp adapter plater is that number I got before 0351178.

I find that on each casting they have 2 different numbers

1977 55HP adapter plate 321509


1975 50HP adapter plate 315450


What does this mean for me and what are my options?? I still need to find out if I can use the 1975 50Hp adapter plate with my 1977 55hp powerhead.

Sorry to keep bugging everyone with this but this is holding up my whole project big time.


Thanks,
DamianJP
 
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