Swapping Head on 1965 40 HP

[elark7]

I bought a used head to replace the bad crank on the one I have. I was going to swap it head for head. The one I bought was suppose to be a 1963. After I got it and looked it over it is very different from mine. It has the cutout switch on the oppisite side and no spot for a fuel pump. I am guessing that it is from an earlier, 1959 and prior, year. My question is will the crank from it work in mine? My motor works but sheared off the woodruff key, it is the third one that has sheared off in the past 6 years, and the piece in the crank is welded to it. And yes I torqued it to factory specs every time. Thanks for the help.

 

[F_R]

Re: Swapping Head on 1965 40 HP

I bought a used head to replace the bad crank on the one I have. I was going to swap it head for head. The one I bought was suppose to be a 1963. After I got it and looked it over it is very different from mine. It has the cutout switch on the oppisite side and no spot for a fuel pump. I am guessing that it is from an earlier, 1959 and prior, year. My question is will the crank from it work in mine? My motor works but sheared off the woodruff key, it is the third one that has sheared off in the past 6 years, and the piece in the crank is welded to it. And yes I torqued it to factory specs every time. Thanks for the help.

If it is earlier than 1960, it isn't a 40hp.

40hp, 1960 - 1961 have a smaller crankshaft than 1962-up. Different flywheels, naturally.
1964-up have a different choke (carburetor), a hot-air stove in the exhaust cover, and different intake manifold. That makes a 1963 considerably different than a 1965.

 

[elark7]

Re: Swapping Head on 1965 40 HP

Thanks FR. I spent many hours combing through the posts and finally found some pictures that match the head. It is identical to the 63 Big Twin 40HP. It has the fuel pump with fuel bowl mounted on the oppisite side with a line running to a vacuum plug. Flywheels, points, coills are the same. So I am going to pull them apart to swap the crank, maybe the pistons, and put new rings and gaskets on it.

 

[tootallofwa]

Re: Swapping Head on 1965 40 HP

See this thread. Some of pictures of a 63' 40hp
http://forums.iboats.com/showthread.php?t=376455

My book says torque to 100-105flb
Good luck with the rebuild!

 

[elark7]

Re: Swapping Head on 1965 40 HP

Tootallofwa, thanks for the link. It was your thread that I refered. I bookmarked the pictures. Watch ebay for an engine or head. I paid $25 for the head I got, no carb or fuel pump, and around $38 to ship. I use this motor on a 14 footer and it does great with me and two sons, 400+lbs, and even pulls a tube.

 

[1946Zephyr]

Re: Swapping Head on 1965 40 HP

The powerhead (if that is what you're refering to) should work fine. It's best to install one that is complete. I once installed a 1968 Evinrude Lark powerhead on a 1959 (35hp) Johnson motor and it worked just fine.

So as far as the fuel pump goes, just take the bypass cover off of your old powerhead and put it on your new powerhead and mount the fuel pump. Plain and simple as that.

 

[elark7]

Re: Swapping Head on 1965 40 HP

1946Zephyr- I must have had a major brain fart when I was looking at the two heads. I have been swapping parts on car motors for years, never crossed my mind to do the same with the powerhead, dohhhh. Swapped the parts and put the new powerhead on and it would not set all the way down. Removed it to see what might be in the crank opening. It looks as though some of the other shaft was left behind in the opening, small piece of metal off to one side. It stops the shaft from seating completely. My thought is either use a drill to remove the spot, staying away from the grooves, or remove 1/8 to 1/4 inch from the top of the shaft. I tried to push the spot out with a screwdriver but it is attached fairly solidly. Any other ideas?

 

[elark7]

Re: Swapping Head on 1965 40 HP

Well this motor is quickly going the way of an anchor. The piece that I thought was blocking the drive shaft came out but had no effect on the powerhead seating all of the way. I used a pencil to measure the deepth of the opening in the crankshaft and there is an 1/8 of an inch difference between the two powerheads. Any thoughts as to why they do not interchange? If I do not get this to work I am going to start striping and listing motor parts on ebay, then start looking for another motor for the boat.

 

[bktheking]

Re: Swapping Head on 1965 40 HP

Well this motor is quickly going the way of an anchor. The piece that I thought was blocking the drive shaft came out but had no effect on the powerhead seating all of the way. I used a pencil to measure the deepth of the opening in the crankshaft and there is an 1/8 of an inch difference between the two powerheads. Any thoughts as to why they do not interchange? If I do not get this to work I am going to start striping and listing motor parts on ebay, then start looking for another motor for the boat.

Well , tootallofwa needs a set of pistons

 

[elark7]

Re: Swapping Head on 1965 40 HP

Well , tootallofwa needs a set of pistons

From what I can see, through the exhaust port on the bottom pistons of both powerheads, the pistons and blocks should be very good when/if I pull them apart.