Johnson Motor ID Help

64osby

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Jul 28, 2009
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Tracked this motor down and considering buying it. The owner is over an hour away and has been trying to help ID it but so far no luck.

No plate, He says the freeze plug has J2405753, with a block letter M inside a square on it. He thought it was a 1972, but now states a 1966. He states it's an 18hp.

I have been searching but can't find any match

He rattled off a couple of part numbers, 304761, which shows as a carb plate inner, and 308364, which shows as a mounting bracket. But I can't find the years for the parts.

He did send this pic
Unknown Johnson 18.jpg

Cowl is broken and the transom mounts are broken, Before I bite I'm trying to see what it would take to put Humpty back together again.
 

kfa4303

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Re: Johnson Motor ID Help

HI 64osby. Yup looks like an FD model motor. They're the old, and much loved OMC 18hp motor that eventually went on to become the 20 hp too. I have a '66 FD-20 and a '65 FD-19 (last year of the 18 hp, I believe). I love my motor and it's probably one of, if not the strongest pound for pound motor ever made (let the debates begin :) ). Assuming it has good compression and all of the major components are there, I say go for it. You should be able to get it up and running again for under $100 and that includes all new ignition, oil seals, carb kit, impeller, etc... There should be a riveted tag on the transom clamp with the model number stamped into it. It's usually on the left hand side. My motor will easily push me along in my 14' aluminum, v-hull runabout-turned-fishing boat at about 20-25 mph and I can run around all day and not use half of a 3 gallon tank. They aren't the most fuel efficient engine, but they're aren't too bad once you get 'em dialed in and they certainly drink less than there "Big Twin" cousins, which are also great motors, but famous gas hogs. Keep us posted.
 

64osby

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Re: Johnson Motor ID Help

kfa - I don't know if you saw what I posted - the cowl is cracked and the transom mount is broke.

The owner says the motor was perfect and ran great but a storm caught his boat and tore the motor off.

I currently have a Fastwin 18 that is being repaired, was looking at this one for extra parts or maybe a fixer upper.

If anything the fuel pump and plate could be used to convert the Fastwin 18. Other parts should also fit I would think.

How available are cowls and transom mounts / clamps.
 

kfa4303

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6,094
Re: Johnson Motor ID Help

While the cowls were a bit more specific as time went by, the transom clamp was pretty universal for years so it should be much easier to find one. Depending on where the crack is, you might actually be able to get an aluminum welder to repair it for less than you might think and it would save you from having to take everything apart just to replace the transom clamp. Check good 'ol ebay and/or aomci.org for parts. I actually have a parts motor (FD-19) myself. I'll give you the cowl, if you can cover shipping. It needs a coat of pant, but is otherwise intact. I'll post some pics of it if you're interested.
 

64osby

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Re: Johnson Motor ID Help

....... I actually have a parts motor (FD-19) myself. I'll give you the cowl, if you can cover shipping. It needs a coat of pant, but is otherwise intact. I'll post some pics of it if you're interested.

No need to post pics at this time. Thanks for the info on the bracket. I'll see what kind of deal I can swing and let you know.
 

Steve A W

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Jun 23, 2009
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Re: Johnson Motor ID Help

64osby
The seller said a storm ripped it from boat,
Did it get submerged?
Just a thought.
Good Luck.
Steve A W
 

64osby

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Re: Johnson Motor ID Help

64osby
The seller said a storm ripped it from boat,
Did it get submerged?
Just a thought.
Good Luck.
Steve A W

Yes it was submerged, Boat was missing 10 days. He had a chain on it. Owner says he pulled lower unit and cleaned it, also pulled plugs and put oil in the cylinders.

I don't know if it could be salvaged but it might be good for parts.
 
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