Stator Status

Back to the 123 Cota after a layoff on 6 months or more. as I worked on (I didn’t say focused) on other bikes.

One of the last things I’d done was to look at the electrics as I wasn’t sure if the spark was timed or good enough to fire the bike adequately. Back to the bike now and the first thing to notice was a complete absence of a spark. Checked the gap first, then removed the flywheel and ran some continuity tests

Montesa Stator

There is both ignition and lighting circuits from the stator, but looking just at the ignition circuit, it is like all trials bike; simple [[Compared with the wiring on the Transalp and any road bike with a battery, starter etc]].

So ignoring the lighting circuit, you’ve basically got the condensor, primary coils and points in parallel joined by a common earth (ie the stator plate). These are then joined and connected to the primary coil in the ignition coil. Simple.

So with the continuity test, you would expect to see continuity at all times from the condensor to the ignition coil connecting wire and then also from the windings on the stator. Given the points circuit is also earthed to the stator place it seems that even with the points open, there is continuity to the ignition coil. Looking at the Clymer manual, you should see 0.6 ohms resistance from the black cable to the earth

However, with these checks done, and a new condensor and points in place, still no spark. The points gap is 0.38mm but for some reason, no generated spark. Without having a spare stator plate cannot really determine if I have a problem.