Johnson RDS-23 1961 40 HP acquired; need general advice

[Rodney Owen]

I am new to this club but based upon posts and responses, seems like all the experts are here.  I just retired and wanted a “project”.  A friend bought a tear-down home in AZ and there was a 1960 Starcraft 15′ with a 1961 Johnson Sea Horse, RDS-23, 40 HP on the back.  Craft last registered in 2013 and clearly baked in the AZ sun, 115 plus degrees for the last 13 years.  Bought a SELOC repair manual and removed lower unit to decrease drag.  I can hand turn the engine, and the starter turns the motor over very slowly, and Harbor Freight compression tester says about 70 PSI each cylinder, no spark.  First question, would anyone ever consider trying to rebuild this engine?  I am enamored with 2 stroke engines (cut my grass with my 1988 Lawnboy to this day), love the power to weight ratio which seems like cannot be reproduced.  I’m “okay-to-good” mechanically but not awesome but just retired and have time and money.  When “done” I want something almost good as new in terms of reliability.  Second question is I don’t see an AOMCI chapter in AZ but does anyone know anyone in AZ that would be willing to take a look and offer some hands on advice (plenty of dollars, whiskey, beers, whatever for thanks).

[labrador-guy]

Hello Rodney welcome!  Those 40’s OMC motors were great motors.  This company sold millions of those baby’s.   Here are some things to consider, they are heavy, they burn fuel at an incredible rate.  Parts are still available, new parts are expensive.  lots of parts on ebay but your always taking a chance on used stuff.   I rebuilt a ’63 Evinrude a few years ago.  Memories kicked in I guess ’cause I learned to water ski behind one of these old timers.   Your motor will probably need coils, fuel lines, fuel pump diaphragm, plug wires, head gasket and lots of love for sure.  If the motor has been setting for a few years the compression means little.  Points are probably dirty.  If you are up for an adventure dive right in!

dale

Time for an engine swap!

[JACQUES]

to service your oldy you may want tp download the Johnson service bible…  which covers your  1961 RDS 23

https://www.socalaomci.com/library/johnson_service_manual_10th_edition.pdf

it is free  and covers all you need  450+ pages you can store or print locally and spring binders.

comes in red or white 🙂     be warned… this is a very addictive hobby !

with all the help here… no reason to give up on it.

 

Joining AOMCI has priviledges 🙂

[Rodney Owen]

Thanks so much … 99% certain I am going all in on this project.  Downloaded the manual and thanks a ton all!  Rod

[JACQUES]

don’T crack it open because you have low compresssion as per labrador-guy’s comment.

 

these oldiesall have the same problems …

cracked coils, bad condensers, points can be cleaned up  and be perfectly good. Check/replace gear oil . creamy oil means water got in but some just refill mid season. Resealing the GC is simple …after you have done a few !

if you change cracked coils install new  plug wires   with 7mmm copper strand ( no carbon wires!)  Clean the carb and  make certain the idle circuit is clear… blast with carb cleaner

see carb bugs….note the rd23  has a high speed orifice plug not a needle …see manual page 169 +

http://www.youtube.com/watch?v=ga1Cjymj6ms&feature=youtu.be

1961 Johnson RD-23 40 hp Outboard Motor Parts

 

 

 

Joining AOMCI has priviledges 🙂

[Don]

OK, don’t know if I trust those low compression readings.  I don’t think this engine has the compression relief feature like earlier models.  Perhaps the HF compression gage is not reading correctly.   You might add some outboard oil to the cylinders and try checking compression again with a different gage.  Have you drained/inspected the gear lube?

These were great engines, and rugged also.

[Gary H.]

Just a note on Harbor Freight compression tester. I purchased one because I needed one in a pinch while remotely working on equipment in the field. I lent my Mac Tools one to a friend who was unavailable for me to get it back right away. I later found out that the HF brand was WAY LOW in the readings. This was confirmed by me by testing the compression with my Mac Tools one when it was returned to me. When the readings were so far off, I borrowed a family member’s Snap On tester which matched my Mac Tools  one. HF was off by at least 20 psi in a high compression engine.

[Don]

Yes, it is important to confirm the powerhead and gearcase are in serviceable condition before getting in too deep on this project.  Compression readings that are even and above 90PSI are probably OK.  Gear lube that is a little milky is “OK” provided you change it more frequently…But, raw water draining out is a bad sign, as is nothing at all draining out when you pull the lube plugs.

Generally speaking, you will want to overhaul the ignition system, clean and rebuild the carb, replace fuel lines, replace the water pump impeller in order to get this engine running reliably.

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