1966 Evinrude Fastwin 18 hp rebuild

[Grantspec]

Hello iBoats,

I have been working on rebuilding a 1966 evinrude fastwin for my 1964 Orlando Clipper fiberglass Jon Boat. My motor must have been ran in salt water because I am having major issues with bolts breaking off. It had good compression before I dissasembled so I figured I would try to save the motor.

5 of the head bolts broke off upon disassembly and I was able to get 4 of them out by welding a nut onto them (this was after drilling the shanks out of the head that was siezed on.

Anyways... 1 of the head bolt holes is now FUBAR'd so I have been looking for either a good powerhead or a new block to stuff my engines internals in. My question is, are the pre 1964 engine blocks compatible with my 1966 pistons/rods/carb/etc...? It seems easier to find the 1950s and early 60s engine blocks and powerheads. I know there is something different about the crank bushings on the older motors but I figure I would ask the experts!

Thanks in advance for the help.

 

[F_R]

Re: 1966 Evinrude Fastwin 18 hp rebuild

I'd say for the most part, they would be compatible. You would have to come up with some specific prospects to be sure. How bad did you mess up that bolt? It may be repairable by a machine shop. I've done some pretty tough cases.

 

[Grantspec]

Re: 1966 Evinrude Fastwin 18 hp rebuild

I think it is salvageable, but the hole would need to be taken up to about 7/16 leaving little wall thickness. I just feel as though a few hours of labor at a machine shop would not be worth it when I could find a usable engine block for less than $100.

Here is my example... Could I put my 1966 internals in this engine block? -> Used Johnson Evinrude OMC 376814 1958 Cylinder and Crankcase 18 HP JC | eBay

It looks exactly the same as my engine block. But I have no way of knowing if the cylinder bore or crankshaft journals are the same sizes.

 

[racerone]

Re: 1966 Evinrude Fastwin 18 hp rebuild

These motors use the same crankshaft from 57 to say 76 or so.---Same bore too.-----These are one of the best / most popular motors for someone to own.---In many areas used parts are cheap and plentiful.

 

[Grantspec]

Re: 1966 Evinrude Fastwin 18 hp rebuild

These motors use the same crankshaft from 57 to say 76 or so.---Same bore too.-----These are one of the best / most popular motors for someone to own.---In many areas used parts are cheap and plentiful.

It seems like a great little motor and I am bound and determined to get this thing running again.

What is the primary difference in the 1964 and older motors that drives the 24:1 oil ratio vs. the 50:1 in the 1965 and later motors?

 

[racerone]

Re: 1966 Evinrude Fastwin 18 hp rebuild

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