No spark after installing 70cc Kit

Hiya, I have a 74' Peugeot 103 with a very simple electrical system. One coil for spark, one for lights. Two wires, one to the plug and one to the lights. Both coils and points were recently replaced and the bike ran perfectly before I messed with it.

I removed the engine, (never took off the flywheel) cleaned everything up, replaced cables, new reeds, installed the new top end and everything got a nice thin coat of oil. Engine spins smooth as silk. I connected a compression tester and gave the engine a spin with my cordless drill, 130 PSI. Decide to give it another spin and check spark. Nothing. Plug wire connection is good at the coil.

I unscrewed the plug cap from the wire and measured resistance through the cap at 47K ohms. For the hell of it with the cap still removed I checked resistance from the plug wire to the engine block. Also 47K ohms...

I checked the meter (and it's fine) retested and same results.

Should there be resistance through the cap? Is the resistance from the wire through the coil to the block just coincidentally the same? Isn't 47K way too high?

Any advice greatly appreciated. Thanks.(edited)

Re: No spark after installing 70cc Kit

Sounds like a wiring issue if you didn't touch anything else

Re: No spark after installing 70cc Kit

I never actually did anything with the spark plug wire. None of the work I did was anywhere near the plug wire. I only examined it after the fact and I discovered the no spark situation.

Re: No spark after installing 70cc Kit

> Larry Baltz Wrote:

> -------------------------------------------------------

> I never actually did anything with the spark plug wire. None of the work

> I did was anywhere near the plug wire. I only examined it after the fact

> and I discovered the no spark situation.

I didn't say plug wire. Kill switch/ground wires are what I was talking about. You had to disconnect the stator wires if you removed the engine right?

Re: No spark after installing 70cc Kit

"I didn't say plug wire. Kill switch/ground wires are what I was talking about. You had to disconnect the stator wires if you removed the engine right?"

On the 1974 103 there are two wires coming out of the stator; the plug wire that is connected to the coil and the 6V+ from the lighting coil. That's it. Simplest wiring schematic there could be. No kill switch, you just stall with the compression release to stop the engine. It's essentially just like a lawn mower engine accept it has a lighting coil.

I guess my question is really about the resistance in the plug wire. Is 47K ohms too high? - OR - Could I have damaged the coil or condenser by spinning the engine for 10 seconds with the plug disconnected?(edited)

1974 Mag-Stator.png

Re: No spark after installing 70cc Kit

Richard Eberline /

47 ohms is to high, or the wrong test. You should have 1.6 to 2.1 ohms on one test.

Then 5800 to 6800 on the other test.

« Go to Topic — end of thread

Want to post in this forum? We'd love to have you join the discussion, but first:

Login or Create Account