40V magneto removal and search for spark

Kevin Ibbetson /

Heres a photo of how I got the mag off. Worked like a charm, just need a couple of hose clamps, a metal rod (I used a socket extension) a piece of wood or metal to distribute the forces so you don't punch a hole in the floorboard and a 3/4" drive socket with a piece of pipe slipped over the end for mechanical advantage and off she comes! Bad news is I'm still searching for that elusive spark that was there when the bike was parked 8 years ago. I've cleaned the main switch to make sure it isn't shorting, had the shop check the coil over, apparently it looks ok to them except for the cracks in the case from exposure to the weather though this was just a regular motorcycle shop, I can't find any burnt , broken or disconnected wires, I've tried a different high tension wire, cap and plug with the same results, and I've done the only check I know of on the condensor that is hooking up an analog multimeter to the coil in the highest resistance range the meter has which in effect charges the condensor with the small amount of current available from the meters battery then reversing the leads to the coil while watching to see if the needle jumps (discharges the coil). That checked out OK though probably not the most definitive test. There seems to be lots of magnetism in the mag, the points were in rough shape so I took then out and filed them flat and reset the gap, no change. I'm getting ready to start exchanging components but of course don't want to spend a bundle needlessly. Any body got any ideas??? Thanks for all your help so far, maybe someone has some used but working parts for sale? It's a 1970 Motobecane "Mobbylette" 40V Thanks again Kevin if this doesn't work I will probably sell the bike as-is.


Re: 40V magneto removal and search for spark

Timing is crucial on Motobecanes. You need to reset it as close to spec as possible. They have a manual at mopedriders.org.

Re: 40V magneto removal and search for spark

there goes Matt, stealing my phrases. "Timing is Crucial"


Re: 40V magneto removal and search for spark

Search for my forum "how to clean the points"... i did it. My moby had the same problem.


www.motoretas.cjb.net (my bikes)

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