40HP RDS-25D (1963) and RDSL-26R (1964) Compatibility

40HP RDS-25D (1963) and RDSL-26R (1964) Compatibility

I need some help from the experts again please?

I have a 1964 Johnson RDSL-26R long shaft that?s all tuned up and running good. I found a 1963 RDS-25D short shaft. I will like to make my ?64 a short shaft. Question is the ?63 lower unit a direct swap with my ?64 lower unit? Also, is the overall compatibility of the ?63 the same as my ?64??good for spare parts??

Thanks again for your help fellas?.

-Will

Re: 40HP RDS-25D (1963) and RDSL-26R (1964) Compatibility

Actually, all you'll need is to replace the driveshaft, water tubes and the shift rod coupler - use the shorter ones from the '63 motor. Oh, looks like the '64 is a factory long shaft - then it will have a long lower shift rod instead of a long coupler, so you'll have to replace the lower shift rod also. If that's the case, it may be easier to just bolt up the entire lower unit from the '63 motor. And, of course, you'll have to remove the leg extension piece. Most other parts should be interchageable. I believe the '63 may have a different choke, but someone else might confirm that. Think it had a hot water choke, and they switched to a hot air choke in '64.

Re: 40HP RDS-25D (1963) and RDSL-26R (1964) Compatibility

Yes, I'm looking to see if I can swap the whole lower unit. I'm going to go look at the motor tomorrow, help on this is greatly appriciated. I'm also trying to figure out if this would be good for a backup parts motor.

Thanks again,
-Will