Topic: 1956 Johnson 30hp Rebuild – Page 2 – Antique Outboard Motor Club,Inc

This topic has 20 replies, 7 voices, and was last updated 2 years, 11 months ago by bobw.

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May 16, 2021 at 9:43 am #238443
fleetwin
Participant
US Member - 2 Years
Yes, this is very confusing indeed….Especially since there is a groove there that the oring fits perfectly into, even on the models that are not supposed to use the oring… Again, the engineering though behind this system escapes me….I could see using an oring (mounted lower so it didn’t plug the vaccum port), in conjunction with the vacuum port “just in case” there is a issue with seal leakage…But, not sealing around the outside of the bearing with an oring, just relying on the vacuum port to pull down the stuff that blows by the bearing, seems like a mistake…
May 16, 2021 at 5:17 pm #238463
bobw
Participant
US Member
I guess I can understand the theory behind how it is supposed to work, but I agree it doesn’t seem like a very good design. But it will go back together the “correct” way.

Bob

1937 Champion D2C Deluxe Lite Twin
1954 Johnson CD-11
1957 Evinrude Fastwin 18
1958 Johnson QD-19
1958 Johnson FD-12
1959 Johnson QD-20

“Every 20 minute job is only a broken bolt away from a 3-day project.”
"Every time you remove a broken or seized bolt an angel gets his wings."
May 17, 2021 at 5:41 pm #238507
bobw
Participant
US Member
OK, got the NOS 1958 connecting rods today, part #377272. Fits and works perfectly with the 1956 wrist pin. I definitely like the larger single roller bearing on the ’58 rod. I’ll also post an ad over in the Classifieds section but I’m now looking for a replacement ’56 piston, part #376794 (or #376795 piston/rod assembly).

Bob

1937 Champion D2C Deluxe Lite Twin
1954 Johnson CD-11
1957 Evinrude Fastwin 18
1958 Johnson QD-19
1958 Johnson FD-12
1959 Johnson QD-20

“Every 20 minute job is only a broken bolt away from a 3-day project.”
"Every time you remove a broken or seized bolt an angel gets his wings."
- This reply was modified 2 years, 11 months ago by Mumbles.
May 17, 2021 at 10:03 pm #238517
olcah
Participant
US Member
Thank you, Great Information and photos.
May 19, 2021 at 11:20 am #238586
bobw
Participant
US Member
Some time long ago, I seem to recall reading some OMC service information that indicated a preferred or recommended orientation for the wrist pin retainer clip, in terms of where the open section of the clip should be located relative to the pin. The enclosed pic shows where how I found the clips positioned but I thought I remember reading that the open section of the clip should be oriented down toward the bottom of the piston skirt. Is there a recommended position for the clip or did I just dream this all up? And BTW, I will be installing new wrist pins and clips as part of this rebuild.

Bob

1937 Champion D2C Deluxe Lite Twin
1954 Johnson CD-11
1957 Evinrude Fastwin 18
1958 Johnson QD-19
1958 Johnson FD-12
1959 Johnson QD-20

“Every 20 minute job is only a broken bolt away from a 3-day project.”
"Every time you remove a broken or seized bolt an angel gets his wings."
- This reply was modified 2 years, 11 months ago by Mumbles.
May 19, 2021 at 6:30 pm #238624
Buccaneer
Participant
US Member
Not sure what it would matter regarding the wrist pin clip, unless something to do with expansion of this piston,
but hopefully someone will know for sure.

Prepare to be boarded!
May 19, 2021 at 9:27 pm #238626
need2fish
Participant
I believe the ’56 JohnnyRude was reborn as the 33 hp (Ski-Twin i think it was. I have one or two in my sister-in-laws basement). Anyway, maybe more recent manuals than your 56 can shed some light on the rods and upper seals. I think the difference between the 30 and 35 is bore, not stroke

I have a cherry ’56 in my cousin’s garage. It’s had all of 10 hours on it and he and I did 9 of it by sneaking it out of the boathouse at 5am to go barefooting behind a 12 Thompson.

Olcah, I have an extra clamshell cowl for an RD-18 and am looking to part ways with it. If it’s something you need, shoot me a PM.
May 19, 2021 at 10:04 pm #238628
bobw
Participant
US Member
I got the con rod and upper bearing questions resolved. Now just need some guidance on my last question re: wrist pin retainer clip orientation.

Bob

1937 Champion D2C Deluxe Lite Twin
1954 Johnson CD-11
1957 Evinrude Fastwin 18
1958 Johnson QD-19
1958 Johnson FD-12
1959 Johnson QD-20

“Every 20 minute job is only a broken bolt away from a 3-day project.”
"Every time you remove a broken or seized bolt an angel gets his wings."
May 24, 2021 at 11:53 pm #238921
bobw
Participant
US Member
Just a follow-up note on the connecting rod upgrade for this RD-18. Digging through some old files, I uncovered my long-forgotten copy of the Johnson Common Parts list and found that the upgraded 377272 con rod is listed as the common part for all models RD18 thru RD21. Lots of good information in this Common Parts list – wish I’d found it earlier!

Bob

1937 Champion D2C Deluxe Lite Twin
1954 Johnson CD-11
1957 Evinrude Fastwin 18
1958 Johnson QD-19
1958 Johnson FD-12
1959 Johnson QD-20

“Every 20 minute job is only a broken bolt away from a 3-day project.”
"Every time you remove a broken or seized bolt an angel gets his wings."
May 25, 2021 at 11:40 am #238956
Mumbles
Participant
On race engines, the retaining ring or clip is oriented with the opening at top or bottom. There’s less chance of it coming out this way at high RPM.
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