Johnson Outboard

Hello everyone...

I just acquired a older Kencraft 14' runabout that has a Johnson 55. The thing that confuses me, and I hope it gets cleared is, this engine has what would appear to be three (3) cylinders.

From my researching the internet in hopes to find a manual for this engine, I have come to the conclusion that this may not be a 55HP engine after all.

The 55 HP engines I have seen are 2 cylinder; have yet to find a three cylinder...

Is there anyway of determining what size this engine is other than the tag?

Thank-you all in advance...

Re: Johnson Outboard

It is a 55 horse, they were made in the late 60s, do a search in this forum, lots of posts on that engine.

Re: Johnson Outboard

The model number should be stamped on what looks like a freeze plug on the block. Post it back here & you will get the year & hp.

Re: Johnson Outboard

Yep, the old 55hp Johnson. Those were built in 1968 and 1969 in that particular model. Decent motors, but the electronic ignition systems are a nightmare P.I.T.A. Mechanically, they were good though. If it was me, I would sell it, while it's running good and go get a 1972 vintage 40hp and put it on there. They're much easier to work on, and even more reliable.

Re: Johnson Outboard

I have a '69 Johnson 55 hp. Three cylinders, three carbs. They are good strong motors. Innovative motors for 1969 with an hydraulic/electric shift system. The coil/power pack tends to fail on them and is expensive to replace.

It's a classic. I wouldn't toss it out just yet.

Re: Johnson Outboard

Yes, exactly right. Very innovative motors and way ahead of their time.....but, the coil/powerpack is the one thing that should prevent the average boater from dealing with it. You are right though, they are good strong runners and excellent motors mechanically, but the ignition set up has driven outboard mechanics nuts for years and many will stay away from them, because of that. I had one come to my assistance that had issues and I talked to a 30+ year technician and he told me that they had to wait till things totally failed, before the problem could be anylized. I'm thinkin....good thing I don't own one then. Like I said, if it runs good...sell it and buy a nice running 40hp twin. Your boating stress will be 99% removed by doing so.

Re: Johnson Outboard

Found it C0577455 - I looked it up and it says 55HP on the Johnson Website. Thanks everyone for your help...
For this engine would 1/2 a liter to 27 gals sound right? 50:1 ratio?

1946Zephyr - Is there an alternative to the ignition system? If the engine is reliable then someone must have made a improved or found a improved alternative... I would think anyway.

Solittle said:

The model number should be stamped on what looks like a freeze plug on the block. Post it back here & you will get the year & hp.

Click to expand...

Re: Johnson Outboard

For 50:1 Gas to Oil mixture it would be 69.12 ounces (2.04 liters) of oil to 27 gallons of gasoline.


http://www.csgnetwork.com/oilfuelcalc.html

Re: Johnson Outboard

todds numbers are correct if the motor is a 50:1 girl. not sure why keogge is mixing metric with standard tho.

Re: Johnson Outboard

Keogge wrote: "Is there an alternative to the ignition system?"

I've seen some of these units modified with an automotive coil. It's a bad idea. The automotive coil can't handle the high duty cycle and overheats. Works good for 10 minutes and then bogs down. After cooling, works again for 10 minutes, etc. It's just a nasty trick to sell it to an unsuspecting buyer.

CDI Electronics have a coil and amplifier kit which, in my opinion, is a better option.

Also, you might want to check the rotor under the flywheel for condition. If it's worn, finding a suitable replacement can be a challenge.

Good luck!

Re: Johnson Outboard

nwcove said:

todds numbers are correct if the motor is a 50:1 girl. not sure why keogge is mixing metric with standard tho.

Click to expand...

My error...

Re: Johnson Outboard

Ok, thank-you very much...

Re: Johnson Outboard

Hi all- just quick word on the "nightmare ignition system" you describe on these motors... I have a '69 55hp, and I think I just woke up from that nightmare. After repairing numerous corroded wires and attempting to save an original power pack with no luck, I went and got an original (60s vintage) replacement from a shop about an hour away, only to find that it too was corroded beyond repair (and still in the original OMC cardboard box!). They swapped it out for a "good used" aftermarket unit, and of course, it was also a $250 paperweight.
After much cursing, drinking, and reading, I came to the conclusion that basically, one CD box is just as good as another, if you think about it. All it is is a capacitor being repeatedly charged and discharged through a transistorized switch, with some form of trigger to operate that switch, right? So I bit the bullet and bought an MSD Street Fire automotive ignition CD box, and wired it up per the instructions it came with, using the points trigger option. Just as I theorized... we had fire! (good fire... not bad fire- lol) Stock coil, stock points, just a different box... and for $138 from the local Advance Auto!
Now here's the "but" part. The MSD is a Multiple Spark Discharge system, meaning more than one spark per firing event. because of this, they recommend removing the "trailing" set of points on a dual point system, so there is only one trigger telling the box what to do. I'm guessing this becomes even more important with a 2 stroke, because it fires twice as often. Also, the box doesn't care how many cylinders an engine has, or if it's 2 stroke or 4 stroke. However, the built in rev limiter does. Leave the box set in 8 cyl mode, and turn the adjustable dials up to max, problem solved.
The only thing that is yet to be seen is the durability of the system. I mounted mine inside the boat, under the splash well to keep it as dry as possible, so it should be fine. We'll see. Can't be much worse than the original Motorola stuff!

I know, I said it was going to be a quick word.... sorry.

Re: Johnson Outboard

That's awesome... I figure there must have been an alternative out there. Keep us posted...

1980SeaNymph said:

Hi all- just quick word on the "nightmare ignition system" you describe on these motors... I have a '69 55hp, and I think I just woke up from that nightmare. After repairing numerous corroded wires and attempting to save an original power pack with no luck, I went and got an original (60s vintage) replacement from a shop about an hour away, only to find that it too was corroded beyond repair (and still in the original OMC cardboard box!). They swapped it out for a "good used" aftermarket unit, and of course, it was also a $250 paperweight.
After much cursing, drinking, and reading, I came to the conclusion that basically, one CD box is just as good as another, if you think about it. All it is is a capacitor being repeatedly charged and discharged through a transistorized switch, with some form of trigger to operate that switch, right? So I bit the bullet and bought an MSD Street Fire automotive ignition CD box, and wired it up per the instructions it came with, using the points trigger option. Just as I theorized... we had fire! (good fire... not bad fire- lol) Stock coil, stock points, just a different box... and for $138 from the local Advance Auto!
Now here's the "but" part. The MSD is a Multiple Spark Discharge system, meaning more than one spark per firing event. because of this, they recommend removing the "trailing" set of points on a dual point system, so there is only one trigger telling the box what to do. I'm guessing this becomes even more important with a 2 stroke, because it fires twice as often. Also, the box doesn't care how many cylinders an engine has, or if it's 2 stroke or 4 stroke. However, the built in rev limiter does. Leave the box set in 8 cyl mode, and turn the adjustable dials up to max, problem solved.
The only thing that is yet to be seen is the durability of the system. I mounted mine inside the boat, under the splash well to keep it as dry as possible, so it should be fine. We'll see. Can't be much worse than the original Motorola stuff!

I know, I said it was going to be a quick word.... sorry.

Click to expand...

Re: Johnson Outboard

Keogge said:

Found it C0577455 - I looked it up and it says 55HP on the Johnson Website. Thanks everyone for your help...
For this engine would 1/2 a liter to 27 gals sound right? 50:1 ratio?

1946Zephyr - Is there an alternative to the ignition system? If the engine is reliable then someone must have made a improved or found a improved alternative... I would think anyway.

Click to expand...

Not with that engine. Like I said, in 1968 and 69, OMC was doing some serious re-designing of their outboards. That 55hp was a revolutionary design for the year. They had the sleek modernized look that was in production for a couple decades. The old style design was on it's way out and these were coming in. 1969, the fat fours did it, with the 85 and 115. Again, totally re-designing the appearance and electronics. It's pretty safe to say, that the electronic ignitions for your 55 hp are pretty much proprietary for the 1968 - 69 years. In 1970, the ignition system was much improved, but the motor was also increased in horsepower as well, plus there were other design changes. In 1971, There was a revolutionary re-design in the big twins as well, when the 50hp came out. These were pretty interesting set ups. A big twin with dual carbs? Pretty wild in the performance category.

So, if it were me, I would just get me a good old 40hp Norseman from about the 1972 vintage and keep your repair costs down with it. It has the old 43.9 cube block, which was a proven design, since 1962 and it has the good hearty gearcase, which is basically unchanged from 1951 and better yet, it has the inexpensive and simple to replace universal style ignition system that has been proven since 1951. This particular model was built with the single wall midsection, so you have a lot less weight than the earlier 40's. These are basically an upgraded version of the old 33hp Ski Twins, but with the 40hp powerhead.

Re: Johnson Outboard

That's really interesting 1946Zephyr; 40hp Norseman eh? I Can't seem to find any around me, there are lots of Johnson's, but real small or real big...
I started my engine up the other day and it ran nice; noisy, but nice... Want to drain the oil in the leg and replace it just to be on the safe side. There seem to be nothing but Tardicons around here. I am trying to find out what oil to use and also purchase a couple trim pins. When I ask I just get a funny look; idjits...
There are/were no trim pins with the boat and in fact a board and bungee cords were used to adjust the trim. Is there a place on the internet where I can purchase a couple that used PayPal? Also, I noticed that the throttle cable lock on the engine is broken and the cable is wired in place. Can parts still be purchased or do I just stay with the wire job?

Thanks again you guys for your help... It is a great thing to be able to have access to your knowledge...

Cheers,