75 horse VS 50 HP Evinrude

Suggestions, concerns, and what is the correct power plant for your Thompson.

Moderators: TDockside, Miles, a j r, Moderators

75 horse VS 50 HP Evinrude

Postby koolminx » Sun Apr 02, 2006 8:10 pm

I have a 1960 Evinrude 75 horse ourboard according to the Serial #. I was told by a fellow that the ENGINE is a 50 Horse Johnson... How can this be true? and How can I tell the diffrence.. Does anyone know the bore and stroke of the 50 Horse Johnson/Evinrude and the 75 horse. Apparently they are both V-4 engines, mine is... I'm in the process of selling it and would appreciate any help. e-mail me at malem2us@comcast.net at anyones earliest opportunity if you have some specs.


Gary (koolminx)
Posts: 2
Joined: Sun Apr 02, 2006 8:05 pm

Postby a j r » Tue Apr 04, 2006 4:19 am

The serial number and model number should indicate the year and HP. www.old-omc.de is one site where this information is listed.

Can't tell you anything about the bore and stroke.
a j r
Posts: 661
Joined: Sat Jan 07, 2006 3:09 pm

Postby JRPfeff » Tue Apr 04, 2006 8:51 am


Is the serial no. from the engine or the lower end? I think they were compatible between the two, and you could have a mixed unit.

Dennis Evinrude can probably help you. Try getting in touch with him through the Antique Outboard Motor Club. I can give his phone number if that doesn't work.

Posts: 78
Joined: Wed Dec 28, 2005 7:26 am
Location: Pewaukee, WI

Postby john » Tue Apr 04, 2006 6:39 pm

50 hp is 70 cubic inch and 75 is 89 cubic inch.

Most noticable difference on engine is choke, 50 hp is electric solenoid, and 75 is hot water choke. Clamp bracket on 50 has thumb screws, 75 has bolt on brackets. 75 has one piece pointed gearcase, 50 has two piece snub nose.
Posts: 261
Joined: Tue Dec 27, 2005 7:33 pm
Location: Crosby (Houston) Texas

Postby koolminx » Sat Sep 10, 2011 5:19 pm

Wow I did end up having a miss matched head and block I think. Thanks for replying, sorry I never got back, we PCS'd back home to Washington and I forgot about this site.
I now actually have a boat and run what I believe is a 1951 Elgin 2.5 horse as a putt around motor for my 1969 Reinell 18' boat.

Just wanted to say thanks for the help I got, and sorry for being a dickweed and forgetting... :)

Posts: 2
Joined: Sun Apr 02, 2006 8:05 pm

Return to Engines

Who is online

Users browsing this forum: No registered users and 26 guests