Topic: Propeller 1956 30 hp – Antique Outboard Motor Club,Inc

This topic has 14 replies, 8 voices, and was last updated 9 years, 5 months ago by billy-t.

Viewing 10 posts - 1 through 10 (of 15 total)

1 2 →

Author

Posts
March 31, 2015 at 2:06 am #1069
billy-t
Participant
hey fellows

Quick question, i just picked up a 1956 30 johnson that is missing the prop, otherwise pretty complete. i believe i have a prop off a 1957 35 hp would that work? if not what should i be looking for?

Thanks
March 31, 2015 at 2:53 am #13086
garry-in-michigan
Participant
Lifetime Member
The 25 & 30 horse motors (1951 through 1956) used a 10-3/8" diameter by 12-½" pitch propeller. The 35 horse motors (1957 – 1959) used a 10-⅜" by 13-¼" prop. You might got away with the higher pitch on a small hydroplane, but not on fiberglass runabout. The 30 horse thrives on high RPM. The higher pitch would not let it turn up to it’s full horse power.

. . . . . . 😉
March 31, 2015 at 3:08 am #13087
beerman57
Participant
3/4" pitch difference isn’t going to make much difference if the motor is on a light boat, more pitch better on a light boat. On a heavy boat, less pitch.
March 31, 2015 at 9:42 am #13090
chinewalker
Participant
US Member
Of course, this is all guesswork, as none of us know what prop you have. Just because the 35 may have been shipped with such and such prop 60 years ago doesn’t mean that’s what is there now. Numbers from the prop hub would help, but in a word, it will fit. Is it correct? Depends on what you’re running it on.
March 31, 2015 at 10:27 am #13091
Randy in Tampa
Participant
I would just put it on and try it, I’m constantly changing props on motors to see which one works best and that one might work best for you, I would put it on and see and if it lugs it’s too much pitch…. 😉
March 31, 2015 at 11:36 am #13094
olcah
Participant
US Member
Interesting question! I plan to run a 1956 Johnson 30 HP on a 12 ft. Crestliner Commander aluminum boat with front steering. Boat weight is about 160 lb. + motor, tank, and me. Will a standard propeller over rev the motor? Would a 13 or 14 pitch be better? Thank you.
March 31, 2015 at 12:36 pm #13097
billy-t
Participant
Thanks for all the thoughts. good point on part number on the propeller I have, will dig it out and have a look.

Thinking that I would be running it on a deep 14 mirrocraft, or a heavier 16 starcraft.

I appreciate the comments, will dig out the prop and have a look and advise what I find.

Thanks again fellows.

woke up to 3 inches of new snow in southern Ontario, might be a few days before i hit the water, still too hard!
March 31, 2015 at 1:22 pm #13098
chinewalker
Participant
US Member
OLCAH – honestly, you won’t know until you try it. It’s a small boat, lightweight. The higher pitch may be better. The BEST way is get as many props as you can get your hands on, buy/borrow an inductive tachometer and TEST, TEST, TEST! The downside of that is you might have to spend a day on the water, running around at high speed. Tough duty, I know, but, hey, it’s gotta be done!
March 31, 2015 at 2:18 pm #13100
olcah
Participant
US Member
Thanks Chinewalker. Somebody has to do it. Might as well be me.
March 31, 2015 at 9:34 pm #13113
billy-t
Participant
Hi well i dug up the propeller from the shed, bit of an adventure that i am sure most have experienced.

The only number i can find on it anywhere is R106 on the side, does that help anyone?

Thanks

Billy T
Author

Posts