No spark on a Wisconsin Robin

m610

Member
I'm not surprised that Wisconsin motors are not listed here. ;)

Anyway, I've got one, WI-185, and it is on a friend's post-hole digger, the earth drill type. It has not been run in years, so I cleaned it up, replaced the rust parts, repaired the fuel cutoff, cleaned the strainer, got it a new carburetor, etc., and now I am ready to fire it up. After more than a few pulls on the crank cable, I pulled the spark plug, and, still connected, I grounded it, and pulled again. No spark. Then I got my spark tester, or whatever it is called, and hooked it up, grounded it, and pulled. I get a strong yellow spark in its window. So now I plug the spark plug into it, ground it, pull, no spark and no light. I try again with a new spark plug, same result. No light and no spark. The best I can figure is I am getting current, just not a high enough voltage to fire a spark plug.

So now what should be my next step?

How do these things generate the power for the spark plug anyway?

Thanks in advance,
Mike
 
I reduced the spark plug gap to next to nothing, and got nothing on my tester. I shorted the spark plug gap and the tester lit up.
 
I would pull the flywheel and check the points and condenser. Set the points at .018” and try again with a new spark plug. If still no spark, I would be leaning towards replacing both points and condenser. Service manual is available online. Look for either WI-185 or EY20, same unit.
 
The fun thing about working on equipment I've never worked on is that I need to buy more tools. ;)

I got the flywheel off, and I don't see points or a capacitor, just the coil. I guess I either need another coil, or magnet or both.

IMG_8518-800.jpgIMG_8516-800.jpg
 
Of course it is a magneto with a self contain ignition coil IE solid state. It is so noted in the service manual.
 
...So now I plug the spark plug into it, ground it, pull, no spark and no light. I try again with a new spark plug, same result.
Did you try another plug? I have seen plugs go bad... If still no go and double checked the magnet is strong, you can find a coil on ebay for cheap. I bought one, so it isn't junk... (or did I just get lucky)

Then again... I have come across a flywheel magnet that appeared to be strong but wouldn't spark and replacing it fixed the problem...
 
I did try another plug. No go.

I found some coils online: used - $20, new and never used - $300+

I wonder if I can recharge the magnet.

Mike
 
I know many say that flywheel magnets go bad, but in my 50+ years of doing small engine repairs I’ve only seen this problem less than a half dozen times. Very rare. Have you tried resetting the air gap slightly tighter, I use .018”.
 
Back
Top