Just picked up a second hand electronic ignition kit for my Cota 200, its one of the Motoplat kits like the ones on the france Classic Trial web site and I was wondering if any one else is using one?

I have fitted it but the spark looks weak and when riding around slowly every so often it just stalls!! I have tried different carbs (new Mikuni and Dellorto) so it is not a carb problem and of course plugs, I also fitted the old points system and all is ok.

I know the flywheel is a lot lighter but that shouldn't let it stall!?!?! Its more like it cuts out rather than stalls and will start easily straight away with one kick.

The main reason for changing to electronic was for reliability and a quicker pickup

Any thoughts???

One interesting thing is the Dellorto I tried was straight off a 125 Gas Gas and (with the points ignition fitted) it ran better than with the new Mikuni I bought last year!!!

Ian

Quite often the spark from electronic ignitions looks weak, they can tend to be almost white or very dark blue in colour, it doesn't mean they aren't working.

You need a darken room to really see them, or try your hand, you'll soon now if it's kicking out enough!

I'd have thought the lighter fly would make it easier to stall as it's the flywheel weight that keeps the motor turning between firings.

Too light and it would not have the inertia to keep running steadily.

It's very noticeable on engines with light flywheels that they don't idle well and seldom run slowly, when's the last time you heard a F1 car idle a 750 rpm?

Have you weighed the stock and replacements?

How much difference is there?

If there is, you could try adding it to the replacement and see if it makes a difference, you can often bolt a flat weight on to the flywheel.

Someones put it more eloquently than me,

"An engine makes the least torque at idle and low rpm, the engine torque is too small to overcome the bike's inertia, and it stalls. If you have a flywheel, the stored momentum augments the engine's torque allowing you to use a lower rpm starting-off. Without a flywheel you'd need a higher idle speed, or constantly need to start-off at a higher rpm in order to raise the engine torque output enough to avoid stalling the engine."

Not familiar with the electronic system you are talking about,but is the air gap set correctly between the flywheel and pickup ? As said the spark from electronic systems can look weaker and whiter than the blue spark from a traditional points/mag set up - the only real way to see what is going on is by using an oscilliscope.From this you can tell the strength and duration of the spark,which needs to be more than 1/2 a millisecond in duration to be sure of lighting the mixture.

Just picked up a second hand electronic ignition kit for my Cota 200, its one of the Motoplat kits like the ones on the france Classic Trial web site and I was wondering if any one else is using one?

I have fitted it but the spark looks weak and when riding around slowly every so often it just stalls!! I have tried different carbs (new Mikuni and Dellorto) so it is not a carb problem and of course plugs, I also fitted the old points system and all is ok.

I know the flywheel is a lot lighter but that shouldn't let it stall!?!?! Its more like it cuts out rather than stalls and will start easily straight away with one kick.

The main reason for changing to electronic was for reliability and a quicker pickup

Any thoughts???

One interesting thing is the Dellorto I tried was straight off a 125 Gas Gas and (with the points ignition fitted) it ran better than with the new Mikuni I bought last year!!!

Ian

I also have a cota 200 and have not had an issue with the stock ignition. The stock flywheel is light for that era. Are you saying that you have changed to a lighter flywheel than stock?

The new flywheel is about 500g lighter, I dont think the weight is the issue as a couple of times i have opened the throttle just as it was about to stall and it just goes borrrrrrrrrrrrrr and stops!!

I will ad a weight just too see what happens though!

Well a flywheel weight has been fitted (its just a bit heavier than stock now) its better but not as good as the points system!!!!

I get a good white / light blue spark from the HT lead that will jump about 10mm when turning the engine over with a windy gun, I just feel its a bit weak a low rpm.

Should I be using a different type of plug? I am using a BPR6ES at the moment?

I was wondering if the new electronic spark is shorter and unable to cope with not quite perfect carburation like the old points system can?

I think I have just got an expensive white elephant!!!!

Should you be using a resistor plug ?

FranceTrialClassic these guys have some nice parts, are well sorted and deliver very fast, but their price pricing* does hurt sometimes.

* I hope that is the right expression

The postage is also pretty amazing (expensive)