Topic: 1951 Johnson HD-26- calling all Johnson experts!

This topic has 10 replies, 7 voices, and was last updated 9 years, 5 months ago by thepetrolist.

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April 9, 2015 at 10:00 am #1146
thepetrolist
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Hi all

I’ve got a 1951 HD-26, 2.5 hp. It’s in a really good shape for its age, runs good and strong. I can’t find almost any info about these engines. They seem to be quite rare. Are they? I’m not inquiring about the value of this engine since I don’t really care about that too much. I have found that its predecessor is the HD-25, made from 1946-1950 and its successor is the JW-10, 3hp, made from 1952 onwards.
Why is this engine rare? Why was it only made that one year (1951)? What are the main differences between the HD-25 and the HD-26?

Any help, info or tips is appreciated!

Niko
April 9, 2015 at 12:23 pm #13614
ggoldy
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The experts are here. I’m afraid I’m not one of them, but I’ll go out on a limb and guess…..you’ll have your answers in 6-8 hours. This is a great place!
April 9, 2015 at 1:30 pm #13616
kees
Participant
International Member - 2 Years
quote thepetrolist:

Hi all

I’ve got a 1951 HD-26, 2.5 hp.Why is this engine rare?

Niko

Maybe there was a very low production in the last year they were made. ❓

for the rest……I don’t know.
there are other experts here
April 10, 2015 at 3:06 am #13652
r-c
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Lifetime Member
I think the difference in model number, is because in 1951 the entire line of OMC’s used the "universal" magneto. The previous HD’s had an internal rotor magnet, with the coil heal facing the rotor. The universal mag had the coil heal facing out to a magnet in the flywheel, what we are use to for all two cylinder OMC’s until CD ignition. The one cylinder 1 1/2 and 2 hp of the 70’s and 80’s also used these parts. Rarity? Probably no, easy to fix yes. The TD and TN has the same model number change because of the mag change. If I remember right the T models had a ratch on the mag advance, one way to tell the difference. I haven’t had to do this; but it measures correct to use a modern OMC coil on the heals of an internal rotor type mag. Whether the coil needs to be faced in or out maybe trial and error or no difference at all. I’m sure somebody has tried this.
April 10, 2015 at 10:31 am #13656
1946zephyr
Participant
I don’t think the HD was ever built with the universal mag. The JW/Lightwin was being developed, when the HD-26 was on the market. If I’m not mistaken, the Evinrude 3.3 Sportwin was also built in 1951, with it’s original style of mag too. There wasn’t any sense in designing these two motors to use the universal mag, for the last year of production. that would have involved a new crankshaft, as well as a new mag plate assembly.
It wasn’t till the following year that all OMC’s were built with the universal mag.
There may have been some cosmetic changes, to warrant the new model number.
April 10, 2015 at 1:52 pm #13658
cajuncook1
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April 10, 2015 at 1:55 pm #13659
cajuncook1
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April 10, 2015 at 5:45 pm #13668
phil
Participant
US Member - 2 Years
Yes, motors I have worked have confirmed to me that, 1952 was the changeover year to the "universal" coil, the latest ones I’ve bought carry an OEM # of 584477 or Sierra 18-5171

http://www.omc-boats.org
http://www.aerocraft-boats.org
April 10, 2015 at 5:54 pm #13670
phil
Participant
US Member - 2 Years
If you need rings for your HD 2.5 hp there are some for sale on the classified section right now at a reasonable price.

http://www.omc-boats.org
http://www.aerocraft-boats.org
April 10, 2015 at 5:59 pm #13671
ggoldy
Participant
There you go, Niko, everything but the actual shop manual, and the parts! It really doesn’t get any better than this forum!
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