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1952 - 1954 Johnson 3 H.P.

Ram Jet

Contributing Member
I just bought a boat with a Johnson 3 H.P. motor. The motor model is JW-10, SN - 980600. I know a JW-10 was made from 52' to 54'. Is there any way to determine the exact year of manufacture? The engine runs pretty well but it does surge a-little bit at 3/4 throttle. Possibly because the carb is dirty or the fuel filter is not flowing properly. I was on the water yesterday and the main return spring in the recoil starter broke and I had to get towed. I don't like this Rube Goldberg recoil starter mechanisim on the 52' and want to install one from a 1960-1964. I think that if I install the 1960 flywheel and recoil starter I should be OK. Am I wrong? Will a 1960 flywheel on a 1952 change the ignition timing?

One thing for sure, I will not go out on the water with my 1960 3 H.P. or my 1952 without a screw driver and a manual pull rope again.

Thanks in advance,

Bill Albertson
 
According to the accepted list, that S/N is a 1952

Sorry about your recoil starter, but some of us do not have a problem with the design. After the first couple hundred, they are easy enough. I actually don't know if the elliptical one will fit your motor or not. I have doubts. If the flywheel fits, it should be ok, but I sort of think it is different around the outer rim. Timing is not an issue.
 
According to the accepted list, that S/N is a 1952

Sorry about your recoil starter, but some of us do not have a problem with the design. After the first couple hundred, they are easy enough. I actually don't know if the elliptical one will fit your motor or not. I have doubts. If the flywheel fits, it should be ok, but I sort of think it is different around the outer rim. Timing is not an issue.

Yeah the flywheels are different. The newer recoil starter will not work without the flywheel also. Not only is the main recoil spring broken on the 52' one of those tiny little springs is broken also. I just don't like the design. The recoil starter on my 60' is better than ANY recoil starter I've seen on anything - including lawnmowers and chain saws. If you think the timing won't be affected I think a later model flywheel will work. Heck, I can swap the gas tanks from my 52' to my 60' and vice versa - and probably the carb, points, coils etc. There's a guy on eBay right now that has a 64' recoil but no flywheel puller to take off the flywheel. I'll keep looking.

Thanks, it's good to know it's a 1952. This has to be one of the first 3 H.P.s in production. The good thing is that it runs pretty well - and it was free. :)

Cheers,

Bill
 
Do you pick up the slack slowly and engage the dogs before pulling the rope hard? I have no less than 15 3 hp of this vintage and as a 50 year veteran in marine repairs, specializing in OMC and Mercury, I have no problem with any of these recoil starters. Make sure the rope is high quality and as long as possible, then keep the motor tuned up properly. I have started these up while showing off with the tank off and spinning the flywheel with my bare hands.
 
Do you pick up the slack slowly and engage the dogs before pulling the rope hard? I have no less than 15 3 hp of this vintage and as a 50 year veteran in marine repairs, specializing in OMC and Mercury, I have no problem with any of these recoil starters. Make sure the rope is high quality and as long as possible, then keep the motor tuned up properly. I have started these up while showing off with the tank off and spinning the flywheel with my bare hands.

I'm 70 years old and have been yanking recoil starters for about 60 years - grew-up on Keuka Lake (New York Finger Lake). Yep. always engage the drive dogs before I pull. However, you never know when the 66 year old main recoil spring is going to give-up-the-ghost. I still say that this 52' recoil starter is far more complicated than it needs to be. The 60' recoil is sweet and simple - I'm a fan of K.I.S.S. especially when it comes to mechanical things - women? forget it. One thing that I think is really cool about the ol' 52' is that the recoil "rope" is actually a steel cable wrapped in a cotton weave housing - break THAT! Anyway, I'm a "gear head" and everything I own and ride is tip top. Hey, anyone want a copy of the original 1952 Johnson 3 H.P. owners manual? I got one with my little 3 H.P.

I don't know why I'm fussing over a Johnson 3 H.P. that I got for free - guess I kinds got attached to is because I restored a 1960 this past winter.011.jpg

Bill
 
Neat stuff, you and I could talk for hours. KISS, yes, Mercury is a great product but in some cases I would consider a bit "overengineered". I love 'em, however. Another thing. If your motor doesn't start by the 3rd pull, you have some tuning to do. When I do a repair here, I guaranty a running motor by the 3rd pull, or they don't have to pay me. Lets put it this way......I have yet to give a free repair with my stupid promise. One more point, I never wind the springs any tighter than needed to retrieve the rope.
 
Neat stuff, you and I could talk for hours. KISS, yes, Mercury is a great product but in some cases I would consider a bit "overengineered". I love 'em, however. Another thing. If your motor doesn't start by the 3rd pull, you have some tuning to do. When I do a repair here, I guaranty a running motor by the 3rd pull, or they don't have to pay me. Lets put it this way......I have yet to give a free repair with my stupid promise. One more point, I never wind the springs any tighter than needed to retrieve the rope.

Thanks for the advice on the on the recoil spring. I hope I find one that I don't have to tear apart. I have always had a "hot rod" mentality and always favored Merc engines. However, the early Mercs with needle bearings, although very cool, don't withstand long periods of storage - especially damp storage. Very often the cranks rust destroying the crankcase seals and then you have a piece of junk. I don't think the average 10 H.P. Hurricane or 20 H.P. Mark 20 would be running today like my 52' and 60' Johnson 3 H.P.s with plain bearings. I'd love to put an old Mark 20 on my 12' aluminum but I doubt I could ever find one that was worth restoring.

Cheers,

Bill
 
Neat stuff, you and I could talk for hours. KISS, yes, Mercury is a great product but in some cases I would consider a bit "overengineered". I love 'em, however. Another thing. If your motor doesn't start by the 3rd pull, you have some tuning to do. When I do a repair here, I guaranty a running motor by the 3rd pull, or they don't have to pay me. Lets put it this way......I have yet to give a free repair with my stupid promise. One more point, I never wind the springs any tighter than needed to retrieve the rope.

Hey Timguy,

You'll get a kick out of this. I made-up a manual pull start cord for my 1952 3 H.P. 4 1/2 inch piece of broom handle and some 1/4" Nylon cord the same length as the 1952 original pull cord. Yesterday I drained all the fuel out of the gas tank and there probably wasn't much in the float bowl, So I decided to test my new pull cord. I wrapped it around the flywheel and gave it a yank. On the "test" stand the little poop fired and ran for about 10 seconds. Three pulls is a good measure - but one pull on an empty tank?

The main reason I'm writing is to see if you would share with me (us) your technique of rebuilding a carb. I know a guy on Long Island, N.Y. who refurbs motorcycle carbs and believe me the Mikuni or Keihin bike carb makes outboard carbs look like a stone axe in the age of lasers. He uses (partially) an ultrasonic cleaner. What's your secret if you care to share it with us.

Cheers,

Bill
 
Neat guy. I love those old Mercs. Imagine a 100 hp "dock buster", on the market today with who they let operate boats now........transmission? Who needs 'em? What happened to common sense? I had one I loved it. Start in gear.....and 'git. Lets go skiing.
As far as rebuilding the little guys, I flat the upper side of float bowl with a file and coat the old cork floats with a lite epoxy. More hints later.
 
Neat guy. I love those old Mercs. Imagine a 100 hp "dock buster", on the market today with who they let operate boats now........transmission? Who needs 'em? What happened to common sense? I had one I loved it. Start in gear.....and 'git. Lets go skiing.
As far as rebuilding the little guys, I flat the upper side of float bowl with a file and coat the old cork floats with a lite epoxy. More hints later.

I agree, reverse and neutral are a convenience but if you are good at handling a boat under power you don't need them - even for docking. Epoxy on a cork float - good idea. I think they used to use shellac. I would probably rather go plastic if you can get one. On my 1960 Johnson when I took off the float bowl one look said the carb was junk. I don't know what the previous owner ran in that poor engine but the gas tank and fuel filter were full of crud - like he ran battery acid in it. I had to "sand blast" the float bowl with a little Badger abrasive hobby gun and about 600 grit aluminum oxide. I put about 750 BBs in the gas tank with lacquer thinner and shook the daylights out of the tank, drained it and did it again and finally rinsed it out with 409 and water. The sintered bronze fuel filter was toast so I cut it off and JB Weld-ed a VW gas tank brass filter screen in it's place. Believe it or not she runs pretty well. Including purchase price I have nearly $500.00 in this little bugger. Then I buy a 12' aluminum boat one week ago and the guy throws-in a running 52' 3 H.P. - just shoot me.

Bill
 
Sweet. I have a 5 hp got at a rummage sale with neutral that runs so great that I put it in the tank to show customers how a 2018 Yamaha should run. Use 64:1 with Amsoil air cooled Saber 100:1 premix. They think I'm a good mechanic.......I tell them NO. That's just great engineering at work. Wonder what that 2018 Yamaha will run like in 2085, hah! Do you think parts would even be available for it? Give me a choice to have either motor to get out of the Ontario bush in a November snowstorm, going 20 miles down a rock choked river........what would you think I would choose? Been there, brother........bulletproof, brilliant engineering.
Great ideas on the carb and fuel system. muriatic acid is my choice for cleaning, then baking soda with hot water. Doing a tank right now. Use it to save many car and truck tanks infected with old ethanol.
 
Hey Timguy,

I went out and bought an expensive gallon of Aluma Kleen and it was not very effective. A waste of money. Then I tired 50/50 muriatic acid, and then full strength acid and a 3M Ultra Fine Sanding Pad (Scotchbright). The 43 year old Sears aluminum boat is looking darn good again. I should have listened to you. I didn't do the baking soda thing but I hosed the hull down with lots of water.

Bill
 
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