Arching between points while running

byrdman76 · Post by **byrdman76** » Wed Sep 10, 2008 9:12 am

I finally got my 305 fired up the other night and I noticed some arching between the right point set. I have new points, condensers, and coils on the bike. The points are gapped on the right side at 14 thou, and the ground strap is running from the capacitor mount to the frame top motor mount. The left isn't sparking at all.

Any ideas guys?

Thanks,

Byrd

e3steve · Post by **e3steve** » Wed Sep 10, 2008 5:06 pm

Usually indicative of a duff or failing condenser -- that's what the condenser (capacitor) is for, to iron out the arcing -- but, as yours is new (or just 'new to you'?), first and foremost clean the points' facings with alcohol or methylated spirit (or petrol); oily facings can cause arcing and, eventually, burning & pitting. Then, if that's not the problem, try swapping the coils and see if the fault moves to the other set. Don't forget to dis' the wiring complete from each coil and swap over!

byrdman76 · Post by **byrdman76** » Wed Sep 10, 2008 10:37 pm

Thanks Steve - I bet your right with the contamination. I use this particular feeler gauge set for checking valve tolerances. It would also explain why the left side isn't arching. I never used the feeler gauge to set the left side point gap - I used a test light.

If thats not it I'll continue on with swapping the ignition components and see if I can get the problem to move to the other side.

The condenser is brand new by the way.

Thanks,

Byrd

byrdman76 · Post by **byrdman76** » Tue Sep 16, 2008 11:02 pm

Fixed the arching issue...

I had media blasted the coil holders and frame. Then I painted them with self etching primer. I realized this when I began using a wire connected to the negative terminal of the battery to test for proper grounding. I went from the ground strap, to the condenser, no change. Then I touched the coil its self and it stopped immediately. I could touch the coil with the wire and then remove it and watch the spark on the point come and go - pretty cool. I sanded the inside of the coil holders and removed the paint on the frame where the coil holders mount. No more sparks.

byrdman76 · Post by **byrdman76** » Tue Sep 16, 2008 11:03 pm

Fixed the arching issue...

I had media blasted the coil holders and frame. Then I painted them with self etching primer. I realized this when I began using a wire connected to the negative terminal of the battery to test for proper grounding. I went from the ground strap, to the condenser, no change. Then I touched the coil its self and it stopped immediately. I could touch the coil with the wire and then remove it and watch the spark on the point come and go - pretty cool. I sanded the inside of the coil holders and removed the paint on the frame where the coil holders mount. No more sparks.

byrdman76 · Post by **byrdman76** » Tue Sep 16, 2008 11:05 pm

Fixed the arching issue...

I had media blasted the coil holders and frame. Then I painted them with self etching primer. I realized this when I began using a wire connected to the negative terminal of the battery to test for proper grounding. I went from the ground strap, to the condenser, no change. Then I touched the coil its self and it stopped immediately. I could touch the coil with the wire and then remove it and watch the spark on the point come and go - pretty cool. I sanded the inside of the coil holders and removed the paint on the frame where the coil holders mount. No more sparks.

e3steve · Post by **e3steve** » Wed Sep 17, 2008 6:49 am

Now, that's one for the archives! Obviously the coil(s) needs a good ground as a 'reference' for sending the spark to, but I'd never have attributed a resistance at the coil body to arcing points, though.

Thanks for the update; "every day's a schoolday"!