Points assit ignition

[Andy_C]

Decided to fit one of those points assist ignitions to my newley acquired TS250.

I fitted a similar unit to my ETZ and it seemed to improve it.

I like these units because they greatly reduces wear on the points and arguably gives a better spark thanks to the electronic switching.

I have fitted it so that by simply disconnecting 3 wires and reconnecting 1 along with the capacitor it will run on points should the unit break down.

I was going to buy the Vellman kit version but for an extra £10 you can buy a ready made potted unit, the unit I bought is from a company called Gammatronix.

Along with this I also fitted a modern blake fuse box as well as giving the wiring a good once over.

[Puffs]

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[Andy_C]

Puffs: https://gammatronixltd.com/epages/bae94 ... /Category3

Hopefully that will explain things.

It is the ignition system that is switched by the points by a very low current, with the high current through the coil switched electronically by the module so should generate a better spark as it is not dependant on the condition of the points and greatly reduces errosion of the points.

It is not CDI hence the term "points assist"

Vellman sell a kit that you can build yourself - http://www.velleman.co.uk/contents/en-u ... otive.html

Hope this clarifies things - I have always fitted these modules to all my points ignition bikes.

[Puffs]

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[Andy_C]

Puffs - you are right, the principle is that the electronics greatly reduce the current though the points, so greatly reduces wear on the switching surfaces. I agree that you will still get mechanical wear on the heel of the points where it rubs against the cam.

As I believe it the electronic curcuit switches faster than the points, this link will take you to a .pdf of the circuit for the system: http://www.velleman.co.uk/manuals/k2543.pdf

Hard to say what benefits you actually notice.

The unit I had on my 251 was intended for a car, and had a switch on it so that it could be switched in / out of circuit. If you flicked the switch you could certainly hear the tickover change, if you went out for a ride and stopped and switched over you could not really notice any difference. I would be interesting to get a bike with one of these units on a Dyno and see if there is a difference.

Any improvement Is probably marginal, given that the TS is only 6V, anything you can do to improve the switching / response time of the ignition system has to be a good thing.

Rember these are not CDI units which do of course give a "fatter" spark so in theory improved combustion - given the relatively low cost of these units perhaps you could try one and see what you think.

[Guesi]

The "fatter" spark will not improve the combustion....
The most important thing is the exact ignition timing.

And this timing will change due to the abrasion of the contact breaker.

Modern electronic ignitions also have ignition timing changing depending on the revs of the engine.

THIS will improve the power output of the engine, not the reducing of the contact wear of the contact breaker.

The only thing that these assist ignitions do is that they expand the checking time for the contact breakers and the ignition timing setting.

[Puffs]

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[Andy_C]

Guesi - partly agree with what you say, correct timing is the most important issue.

So it follows that anything that can be done to keep the spark accurrate has to be a good thing, which the electronic module should do as it should reduce points erosion.

"Fatter spark" - surley a better / "fatter" spark has to be a good thing.

If you want to light a fire it usually starts better if you have a decent source of combustion, i,e, a "fatter" spark.

[breakwellmz]

I ran my Jawa 350 (6v system) with a 12v battery through the ignition system and that ran noticeably stronger which i can only assume was down to a better spark.

[Puffs]

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[Guesi]

Guesi - partly agree with what you say, correct timing is the most important issue.

So it follows that anything that can be done to keep the spark accurrate has to be a good thing, which the electronic module should do as it should reduce points erosion.

"Fatter spark" - surley a better / "fatter" spark has to be a good thing.

If you want to light a fire it usually starts better if you have a decent source of combustion, i,e, a "fatter" spark.

You are right, but an electronic ignition does it better than this electronic mudule....

[Guesi]

Guesi, would you know more about this; would you have an advance curve for any of the commercially available electronic ignitions for the TS/ETZ?

You mean like this one ?

[breakwellmz]

Hmm, a Jawa 350 (6v system) with a 12v battery. How does that work? How do you charge a 12V battery with a 6V dynamo?

Andy, yes erosion will impact the timing, but only on the somewhat longer term. It's not a major problem for a standard MZ, but vibration & clearance cause inaccuracies in the opening right from the start, and that's where an EI brings benefit, particularly in the higher rev range.

On the strength of the spark: it really only has to ignite the gas right around the plug's electrodes, physics does the rest. And visually stronger need not necessarily bring you a lot, see also https://www.powerdynamo.biz/eng/info/spark.htm .

I didn`t charge it, i simply ran 12 volts through 6 volt coils and noticed a performance improvement, nothing else was changed. I then put a 6v battery back in a the performance reduced, as simple as that.

[Puffs]

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[breakwellmz]

Electric motor?! You need to get out more Puffs! https://www.youtube.com/watch?v=QrrIRr9arkM