15HP Johnson - Will Not Start

[Ruler2112]

I purchased a 15 horse 1991 Johnson long shaft outboard engine, model J15REIA, at a garage sale over the summer that did not start. According to the guy I bought it from, it ran fine the last time it was in the water, but had sat for several years without being run. It turns over fine, so I figured that the carb was just gummed up & that I'd be able to clean it up and get it running.

To begin with, I built a stand for it and proceeded to clean everything. Zebra mussels, grease, dirt, gunk, etc - all gone and the motor is nice & clean now. While doing so, I noticed that the shaft that controls the choke was not connected to the lever inside that actuates the butterfly! Could it be that's all that was wrong with this engine?!???

Unfortunately no. I put the lever in the groove in the plastic shaft & it would not start. I proceeded to do basic troubleshooting and discovered two things.

1) It has no spark. Replacing the spark plugs did nothing and grounding a plug against the engine & pulling resulted in no spark jumping the plug gap.

2) It pulls considerably harder than my 1985 25 horse electric start Evinrude when using the rope instead of the starter.


While I understand the principles involved and pick things up quickly, I am not nearly as good with 2-cycle engines as I am with 4-stroke. I believe the first issue to start troubleshooting has got to be the spark issue, but don't really know where to begin. I would like to get this engine going so that I can have it for either a kicker or backup to my Evinrude. (Evinrude wouldn't start this spring, but I was able to fix it.) I certainly don't mind getting my hands dirty and spending time working to figure things out, but also don't want to sink hundreds of dollars into it. I have an old outboard manual that covers 2-40 horse Johnson/Evinrude engines from 1973-1990, but it obviously stops one year too soon and is rather hard to follow given all the different engines it covers.

Could anybody make recommendations of what my next step should be?

 

[gm280]

Is there a kill switch on the engine, or a lanyard type switch? If so is it set to allow the engine to crank? If you have both cylinders dead without spark, the odds of both spark coils going bad at the exact same time are pretty remote. So I would look for whatever powers or fires the spark coils for the common lack of spark issue. JMHO

Also I would most certainly buy the factory shop manual for that engine and everything you could ever want to know would be in that manual, even theory of operation!

 

[boobie]

Go to cdielectronics.com for ign trouble shooting.

 

[oldboat1]

couple of thoughts -- need an adjustable spark tester for this and future projects (cheap -- maybe $10 at an auto parts store). If you can decipher '90 info in your manual, that should work for the '91.

You will want to pull off the lower unit and replace the impeller anyway, so would check to see if the hard cranking is a lower unit issue (could be more zebra mussels, or debris in the impeller housing, for example). Drain the lower unit oil and see if there is water in it (milky color). When the lower unit is off, run water up the exhaust tube and see if it circulates down and out the leg. Take a flashlight and look up the leg under the powerhead for more debris, and clean it out some.

 

[scout-j-m]

The attached pic is of a tiller handle for a 1991 model. The small red knob is the kill switch. There is a clip that goes in behind it that must be present to run. It connects t the emergency kill lanyard that you wear to kill the engine in the event you go overboard. So if you are missing that then that is the likely culprit of the no spark.

 

[Ruler2112]

The attached pic is of a tiller handle for a 1991 model. The small red knob is the kill switch. There is a clip that goes in behind it that must be present to run. It connects t the emergency kill lanyard that you wear to kill the engine in the event you go overboard. So if you are missing that then that is the likely culprit of the no spark.

It doesn't look like the clip exists on my engine. Is it possible to bypass for testing? If so, how would I go about doing this? Here's what it looks like (please excuse the mess from all the stuff from my boat in the background):

 

[bspeth]

see if you can pull it out and wedge something under it to hold it out,then recheck.

 

[interalian]

Can you ask the seller if he has the clip?

 

[Ruler2112]

I should be able to machine something to fit in there...

Highly doubt if I could get the clip from the seller. Assuming I could find the house I bought it from, the dad was selling it for his kid. No gas can, hose, clips, literature, or anything.

 

[oldboat1]

or can order it easily enough: http://www.iboats.com/Steering-Hand...810104--session_id.454594208--view_id.1536988

 

[kodibass]

Follow the kill switch wires, one will go to ground on the block, unbolt that wire and make sure it is not touching anything, then re-check for spark.. If still no spark CDI troubleshooter says suspect power pack ,, kodi

 

[Tim Frank]

Just a thought....my 1990 8HP has an emergency clip that is mounted near the base of the tiller handle. Don't know if the 15 HPs do as well, but maybe have a look.

Edit: by "emergency" I mean it is a "spare"

 

[AlTn]

in kodi's line of thought...follow the wiring from the stop switch back and you should find a plastic threaded connector..unscrew the connector and you will have separated the stop wire to the power pack...if you do not have spark now, cdielectronics.com/troubleshooting may be beneficial

 

[Ruler2112]

Well, I took a scrap piece of wood, drilled a hole in the end, extended the hole out the end, then carved a slant on the legs - took all of about 3 minutes total. Wedged it into the cutoff switch, pulled a plug, grounded it to the engine, and had a buddy pull it. Not only did I see the spark jump, I got woken up! I'll use the piece of wood until I get the engine running, then machine something more precision out of a material that's dimensionally stable like aluminum or plastic.

So the spark problem is fixed, now I just have to figure out why it's pulling so hard & try to get it running. Lugged the thing down the steps into my basement workshop; plan on pulling the lower unit tonight. Hopefully, it'll turn out to be something as simple as the spark issue.

 

[Ruler2112]

Now that I think about it, I probably won't have to machine a new safety switch - just disconnect the wire from the engine as directed above & cap it off somehow.

 

[interalian]

I woudn't want to "rush" things with that solution. The lanyard is for your safety underway, otherwise it might be a "farewell to kings".

 

[Ruler2112]

Honestly, I'm not really concerned about the lanyard safety cutoff. My 25hp Evinrude has no such feature & as fast as I've gone in my little boat on the bay, never been anywhere near falling out. (I'm 240 pounds and so don't bounce well. ) Even if I had the lanyard, I really don't think I'd use it.



Think I discovered the problem of it pulling hard, or at least part of it. I pulled both plugs and the flywheel turned relatively easily. Put either plug in and it would turn hard at the same point in the rotation. I could hear a faint wooshing sound, like air moving through a small opening. Would I be correct in thinking that this is compression taking place? Is there such a thing as too much compression? If so, what would cause it?

I looked inside with a flashlight & saw that the cylinders looked dry. Shot a squirt of WD40 in each and the flywheel turned MUCH easier. It now pulls easier too.

Given that it's sat for so long and probably not properly winterized, my guess is that the carb is gummed up. While I certainly don't mind dropping some cash on a carb kit & impeller kit for it, I don't want to do so if I'm not going to be able to make it work. Is there anything else I can do to test the engine before buying the kits? Somebody at work suggested squirting some gas in the plug holes and pulling it to see if it runs, but had never done this - he'd just heard about it.

 

[Tim Frank]

The lanyard is never needed until it is.... (I speak after a life-saving incident)

For $5- each, it does not seem worthwhile to DIY on that part....probably a false economy, but your call.

You have not really verified that you have a good spark...just that there is some. as was suggested in an earlier post, you need a proper spark tester....spark should jump 7/16" gap. The old lean-the-plug-against -the-block ' doesn't cut it.

Same with compression. Use a proper gauge to test... so you know where you are.

Once you are sure that spark and compression are really OK, move on to fuel.
You can spray some 50:1 pre-mix into the carb throat and see what happens.....and move on from there.

There is no substitute for systematic troubleshooting.

 

[AlTn]

don't negate the stop switch function by leaving it disconnected....that is useful only as a testing procedure