62 Johnson 28hp--No Spark

[ClayPots]

I've spent most of the weekend reading archived posts but I'm not finding the clues I need for my limited knowledge. I have taken my 28-HP, '62 Johnson out of extended storage and am trying to get it running again. It was running fine when I put it up but that was several years ago. Does this sound like a familiar lament? :-( Right now I have no spark. The points coils and condensers were near new before. The points are clean. There's no corrosion or fouling between the flywheel magnets and the coils. The coils show no cracks in insulation. The kill switch is not shorted. There's no visible problem with any of the wiring insulation. Any suggestions on where I should look for the problem? Thanks in advance!

 

[samo_ott]

Re: 62 Johnson 28hp--No Spark

Hmmm, it sounds like you done a lot already... Have you verified the wires work ok? Is there any way the kill wires have shorted out or crossed? Are you 100% sure the coils work? Have you tried using an ohmmeter to verify the points are electrically opening and closing? Just quick thoughts here...

 

[ClayPots]

Re: 62 Johnson 28hp--No Spark

samo ott,
Thanks for your quick reply. First, I will take another look at the wires to the kill switch, but when I checked with an ohmmeter the switch was open, and only shorted when I depressed the switch, so it appears to work OK. I will look again...it is so obviously a potential cause.
Second, no I haven't looked at the points with a meter, not even sure how to do that. When I pulled the flywheel I looked down on the points and as I rotated the shaft the points opened and closed in a manner that looked normal to me.
You mention checking the wires...I assume you mean the spark plug wires? I am guessing that to check those wires I would have to pull the plate the coils are attached to, then remove the spark plug wires from the coils and check the wires for continuity? I hesitated there because I am not sure I could get the coils back in the right spot, also not sure exactly which fasteners hold the plate down, and finally, thought there might be something more obvious to check first. As you can see, I'm in over my head here.

 

[samo_ott]

Re: 62 Johnson 28hp--No Spark

Unfortunately as you have tried the easy stuff, you'll hafta start trying the harder stuff... Or the more rare stuff... I wouldn't think it was the spark plug wires but it is an option... and for both to go at the same time? That's the strange thing here also... as there are 2 completely separate ignition systems in there usually 1 will work and the other won't... there's very few common areas other than the kill switch, the flywheel... are you sure there no trace of a spark on either side? Are the coils mounted in the right place and aligned? you must have overlooked something... the system is quite basic... you're sure it worked when you stored it? Who changed the coils/points/condensers?

 

[ClayPots]

Re: 62 Johnson 28hp--No Spark

I agree about the "harder stuff." The electrical work was a shop job, Evinrude dealer, and I ran the motor quite a bit for a couple of months afterwards, then put it up for the season. So I know it was running well the day I put it away. So, I must be overlooking something, as you say. No, I am not completely certain there is no trace of a spark on either plug. I am thinking right now that rather than tear into this further I would replace the flywheel and try to test the spark to remove all doubt. Does that make sense? Thanks for your thoughts on this.

 

[tashasdaddy]

Re: 62 Johnson 28hp--No Spark

is this a tiller, motor or remote control motor. if remote control disconnect the wiring harness plug, and try it. also try cleaning your points contacts with a fine file, or emeryboard.

 

[ClayPots]

Re: 62 Johnson 28hp--No Spark

It's not remote, so there's no wiring harness. I will dress the points, for certain. Thanks for the reminder!

 

[tashasdaddy]

Re: 62 Johnson 28hp--No Spark

also points should be set so a .020 will go thru and .022 will not.

 

[F_R]

Re: 62 Johnson 28hp--No Spark

I would be willing to bet the points are corroded. Either clean or replace them or at least test them with your ohmmeter. If your ohmeter is capable of reading less than one ohm, connect one lead to the wires screw on the points and ground the other lead to the armature plate. With the points closed it should read zero ohms. With the points open it should read more than zero but less than one ohm.

However if your meter won't read <1 ohm, you will have to first disconnect the wires from the points. Then it will be zero /closed and infinity/open.

 

[ClayPots]

Re: 62 Johnson 28hp--No Spark

OK, I got some resistance with the points closed so I pulled them and found some fine grey oxidation. I put them back in and cleaned them. I'll check the gap, reset if needed, and try this. Thanks!

 

[ClayPots]

Re: 62 Johnson 28hp--No Spark

All three of your pointed out what was obvious to you but not to me. Namely, the points needed cleaning! Now that's done one cylinder has good spark (~7/16" gap). Unfortunately, the other spark is weak and intermittent, spark present ~20% of the time. I will concentrate on the wiring and components to that cylinder. Samo ott, tashasdaddy, and imported F R, I am very, very grateful for your input and heading me in the right direction. Thanks!

 

[samo_ott]

Re: 62 Johnson 28hp--No Spark

If the 2nd one is weak it'a a coil, if it's intermittent it's a loose wire, connection or coil... usually keep going, you're getting closer!

 

[iwombat]

Re: 62 Johnson 28hp--No Spark

could also be a bad condenser. Do your points on that side look a little toasty?

 

[cougar1985]

Re: 62 Johnson 28hp--No Spark

just food for thought.a complete tune up kit for that motor is about 70 dollars,that includes points condencers and coils,it is well worth it expecially if you suspect that whats in there is original.go with the aftermarket coils from sierra as they are better made than the originals.also a manual is invaluable .

 

[F_R]

Re: 62 Johnson 28hp--No Spark

Maybe you are expecting too much. 7/16" is extraordinary good spark but not necessarily normal on a magneto. That would be expected on a CD electronic ignition, but not a mag. 1/4" is OK.

 

[ClayPots]

Re: 62 Johnson 28hp--No Spark

cougar1985, I appreciate your input. Is there a simple way for me to tell the difference between OMC and Sierra coils? I agree a manual is a must! It's on order... In the meantime I have taken the simple step of disconnecting the wiring from each set of points and cleaning the surfaces of the lugs with fine grit paper. Right now I seem to have good voltage to both plugs! F R, I would have been happy with a consistent, weak spark at this point, did start with about 3/16-gap on the tester, just kept opening that gap to see how far it would go. From the archives I read that over 15,000 volts would be OK, I seem to have 20,000 on both so I am very pleased...so far...fingers crossed...

 

[ClayPots]

Re: 62 Johnson 28hp--No Spark

Thanks to the encouragement of you guys, and the tips, I had the confidence to dig into this and the result...IT RUNS! Hee, hee, hee!