Getting confused

I've been searching (Google and here) for info on a (supposedly) 1968 35 hp Super Seahorse that came with a boat I was given.

Mostly I want to "go through" the engine and make sure everything is up to snuff. Carb kit, water pump impeller, fuel pump, the usual.

Looking at the plate, which is almost impossible to see, (the damn thing is under the casting near where the steering cable(s) hooks up), I get: RDS 21 and, I think, B. Serial number is 1935056. It's elect start, elect choke, short shaft. The problem is, I keep getting 1958-59 for the year when searching and the parts listings skip from 59' to 72'. Not sure what's up with that? I just want to make sure I get the correct parts.

Pic of the outboard:




Help!????

Re: Getting confused

Hi wine. Look on the transom clamp for a small riveted, metal tag, which should list the model and serial number. At a glance, I'd say it's a '59-'60 RD-21 model based on the chrome ring on the cowl, but I could be wrong. Thankfully, most OMC "Big Twin" motors of this era are easy to repair and maintain. Assuming the compression is ok (over 100 psi), everything else is pretty easy to fix. Here are some handy links.

Reviving a Vintage Big Twin - Part 1

1959 Johnson RD-21 35 hp Outboard Motor Parts

Re: Getting confused

Your engine (simply looking at the picture) is a 1959 35hp, Model RDS-21 Johnson.

Re: Getting confused

RDS-21 is 1959 35 HP

see following link for part breakouts:

1959 Johnson RDSL-21 35 hp Outboard Motor Parts

Re: Getting confused

Well, how about that. TY guys!

The compression is 120 lb in each cylinder, and, after cleaning up the cabling (plug), runs pretty well, for sitting since 1986.

Re: Getting confused

Awesome! Glad you got her running wine. Make sure you're using 24:1 mix for your fuel and Champion J6C plugs. In the future, You can get any routine parts you may need like carb kits, tune up kits, waterpumps, etc... right here at iboats for about $20 each. Happy Boating! Vroom-vroom......

Re: Getting confused

No offense intended towards member "kfa4303" here. That powerhead incorporates all needle, roller and/or ball bearings on all of its moving parts (Mains, C/Rods to C/Shaft, Wrist Pins,) and as such, you can safely use the 50/1 mixture if you so desire.

Re: Getting confused

You can also safely use Champion J4C plugs, which were original equipment. Gap them at .030" for normal use, .040" for low speed or trolling use.