What Year is My Johnson ?

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HoldinMyHorses

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Hello, I just bought a Johnson 40 Super Sea Horse. It's a pull start motor. The model number is RD-27M. I would like to know what year it is. Also,I would like to know where I can get a manual so I can get started on bringing it back to life. Any help will be appreciated. <br /><br />Thanks in advance,<br />HoldingMyHorses
 
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ob

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Aug 16, 2002
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Re: What Year is My Johnson ?

1965 model.You can order a manual at the bottom of this page.
 
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Paul Moir

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Re: What Year is My Johnson ?

Johnson RD-27<br />Year 1965<br />HP 40<br />WOT RPMS 4500<br />Displacement 43.9 cu.in. = 719.4 ccm<br />Cylinders 2<br />Weight 132 - 154 lbs. = 59.9 - 69.9 Kg<br />Gear ratio 12:21<br />Fuel:Oil ratio 50:1 87 octane gas to TCW-3 rated outboard oil<br />Spark plugs: Champion J4C (was J4J) gapped at .030"<br /><br />You can buy an aftermarket manual here at iboats. I personally prefer the Seloc one for your outboard. They are geared toward people unfamiliar with mechanics, sort of like a Haynes automotive manual.<br />The OEM manuals are technically superior. You can get reprints:<br />TheOutboardWizard<br />Mastertech<br />Marine Engine<br />Ken Cook <br />Sometimes you can find OEM manuals used on ebay for a fraction of the cost of a reprint.<br /><br />Hope this helps!<br /><br />EDIT: Pardon me, ob!
 
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HoldinMyHorses

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Re: What Year is My Johnson ?

One last question. It appears to be a long shaft motor. It this motor a long shaft ?<br /><br />Thanks again,<br />HoldinMyHorses
 
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Paul Moir

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Re: What Year is My Johnson ?

That's kind of a tough one to answer. <br />If it's a longshaft, there would be a separate, 5" section between the lower unit and the exhaust housing/mid section. A little extension peice in other words.<br />A shortshaft motor normally has approximately 15" between the top of the transom clamp (ie, where the top of the boat transom would contact the transom clamp) and the antiventilation plate, directly above the propeller. The big twins I've measured are closer to 18" between these two points. A standard longshaft is 20".<br />So think of it as a long shortshaft. It can benifit from being raised higher, just make sure it pumps water at idle and full throttle. :)
 
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HoldinMyHorses

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Re: What Year is My Johnson ?

Ok,thanks. Is it possible to put in the 5" piece to make it a true long shaft ? Aren't shaft sizes standard ?
 
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Paul Moir

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Re: What Year is My Johnson ?

Yeah, they're standard. This one is just a little deeper. :) <br />Seriously, if you look at where the water pump is in relation to the a/v plate, you'll notice it's higher than most outboards. I guess this is where the extra couple inches come from.<br />The 5" extension consists of the extension itself, a longer driveshaft, a brass shift rod extension, and longer water tubes. If you can round up all that and put it on, you end up with 22-23" to the antiventilation plate.<br />You may want to investigate the possibility of lowering your engine somehow 2 or 3". Mabey with a jackplate?
 
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HoldinMyHorses

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Re: What Year is My Johnson ?

Ah nevermind, I looked it up. But it seems that it's only for making long shafts/short transoms work. Can it be reversed ?
 
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Paul Moir

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Re: What Year is My Johnson ?

I was just thinking you could mount one lower down on the transom. But you might need room for tilting and control cables. You could perhaps make that room by spacing the jack plate back off the transom a ways. But this is getting into $custom fabrication territory$. You might just want to get in contact with the folks at Twin city outboards and see if they have the extension and paraphernalia you need.
 
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