Points arcing = bad condenser?

[new2mercs]

I've got a Kiekhaefer 4D-5 magneto that I'm troubleshooting. It will throw a spark from the coil contact to ground about 1/4-inch, which seems weak from what I read here. (It's supposed to be about 1/2-inch, right?) I'm seeing a pretty good spark across the contacts when the points open: Does that indicate a bad condenser? Seems like I recall the condenser is supposed to absorb excess juice to keep the points from pitting and these were pretty rough before I cleaned them up... .

 

[Laddies]

Re: Points arcing = bad condenser?

With a small spark like that from the coil you need to test it and the condenser with a Merc o tronic.

 

[new2mercs]

Re: Points arcing = bad condenser?

Thanks Laddies, that helps some, but I'm not sure whether my local dealer would have a Merc O Tronic. Any idea whether I could diagnose with an oscilloscope and a VOM? Seems like I'm looking for a few Kohms across the secondary and a few tenths on the primary; firing voltage should be about 20Kv?

 

[Laddies]

Re: Points arcing = bad condenser?

Most any small engine shop that services magnetos should have a mag analizer either a Merc o tronic or Stevens they both work the same the firing amperage for that mag is 1.8 or less off the plate and secondary continuity is 55 to 65 OHMs. The condenser should test .28 to .35 Mfd.