Scooterotica

firekdp wrote:

J1MS wrote:It's a fix that works, especially on a failing points coil ignition.

I wouldn't have thought that it would work at all on a points system, as there is no output from the ignition coil except for one pos pulse, therefore the voltage doubling capacitor would never receive a charge.

Not going into the tech side of it, but if you have a lammy with a weak spark the air gap holds the spark back a little before it jumps the gap creating a spark that can start an engine, when before it struggled.
Used it on Motoplat and Ducati systems and it's worked.
I use the oldSkool way of two self tappers into the cut ends of the HT and some petrol pipe with small fuelpipe clips used to set the gap.

Its a very well known cure used in the days of old, used by bikes and scooters. Even an article in motorcyle scooter and three wheeler, if my memory serves me well.

I know few other simple test for checking ignition sparks. It's possible to check the polarity of the ignition at the plug end without any sort of meter.

Some of the other oldSkoolers on the forum most likely know much more seemingly forgotten stuff, that most likely would still prove good today.

J1MS wrote:Not going into the tech side of it, but if you have a lammy with a weak spark the air gap holds the spark back a little before it jumps the gap creating a spark that can start an engine, when before it struggled.
Used it on Motoplat and Ducati systems and it's worked.
I use the oldSkool way of two self tappers into the cut ends of the HT and some petrol pipe with small fuelpipe clips used to set the gap.

Its a very well known cure used in the days of old, used by bikes and scooters. Even an article in motorcyle scooter and three wheeler, if my memory serves me well.

I know few other simple test for checking ignition sparks. It's possible to check the polarity of the ignition at the plug end without any sort of meter.

Some of the other oldSkoolers on the forum most likely know much more seemingly forgotten stuff, that most likely would still prove good today.

I see, so when you said it works, you weren't referring to the voltage doubler in the thread but just a cap, so similar to the version bristolmod posted. I wish someone would explain the tech side of that because I fail to see how making the spark jump an extra air gap would make it stronger at the plug, I would have thought the opposite would occur.

it works on ac and dc electrics, to the question of both what....

Both scooter config setups

To summarize,

No magic, it is an easy EE trick that basically internally double (in theory) the voltage on the primary of the coil. The internal components can handle that.
In practice, you get between 20 to 60% more voltage, so it means a lot more energy on the spark.
As for the facts, your scooter will be easier to start and overall will run more smoothly.
Ideally one could also increase the sparkplug gap and slightly overjet to get some 1 digit percentage perf. increase.

You can build your own (schematic and topics here or there) or buy an "integrated" one from me.

Any questions ? Shoot !

KTy wrote: Any questions ? Shoot !

Where's me gun

No expert, so I'm struggling to see why a spark with more energy would be needed? The purpose of the spark is just to ignite the air/fuel mix around it, then this flame front should then smoothly spread through the rest of the mixture. Once the mixture is ignited, that's it, it's done its job, what difference does the size of the spark make? So unless there is is a problem with the ignition circuit and the spark is too weak to start the burn, apart from being an excellent little earner for you (no offence) I fail to see any benefit,
Is the spark igniting more of the mix initially making the burning more rapid? if it is wouldn't it be the same as running with the mixture slightly weaker?

greetings KTy. how goes your spark advance unit?

FWIW, i run one of these,

it's a nology "hot wire". there is a capacitor built into the wire which provides a shorter and more intense spark.
the way i figure it, it's a different means to the same end, this and the SM.
the hot wire seems to give a more complete burn, better idle and throttle response. when i installed the thing, i went up a couple points in the main but i haven't messed with it since. that's after four years. on the tin they claim that the more efficient burn of a rich mixture cools the engine, so there you go.

"My" circuit is different compared to a "Nology", even though the result is similar.

The point is that, with our Electronic AC ignition, the primary "high" voltage is around 120V AC at idle, goes up to 150-180VAC at some resonance rpm (~3-4000rpm) then starts to lower again to end up around 100V AC.
I think your reasoning is pretty accurate concerning the front flame and stuff, but, there are some timing constants and this is also where having a high voltage helps; When the capacitor discharge into the coil (CDI=Capacitive Discharge Ignition), the higher it is, the longer it will take and hence, the better the burning should be.
So, Higher energy and longer spark help burning most of the mixture.

I have to mention that it is really config dependent; some people really experience some enhancement, some others just mention a "smoother" engine, finally some (few to be honest) do not "feel" nothing...

I've ordered my bits - so i'll have a go at makin a couple up -

well if i get just one result from what some users have said i will be happy, easier starting or better low rpm pickup, less emisssion or smoother engine to stop my arse gettin numb i'll take it oh as well as giving the techies some fat to chew....priceless