ignition coil modifications?

[tyler_jrn]

I'm changing my CDI and ignition coil on my bike as the CDI basically fell off and ground into my wheel and the ignition coil is cracked in places and i have noticed sparks coming from the cap on the spark plug to the engine, most likely the reason behind power drops ive been having.

Also my bike is a 125cc zontes bike, i know Chinese but all i had the choice to get or a 50cc moped. besides its never broken down.

My questions are the ignition coil with cable i have is about 450-500mm long, whereas the performance one im looking at is around 350mm long so will be a very tight fit, there are no ones longer than this.

Is there any way say to remove the cable from the ignition coil and replace with a longer one with a better NGK ignition cap on the end?

It has an ngk cap on the end atm so im guessing the cap can be changed but can the cable length be increased? So it will fit comfortably onto my bike.

i have a good week off soon so wanting to get carb set up, ignition all set up before my holidays run out.

if it cannot be increased im guessing ill have to get the stock one, and put a new NGK ignition cap on the end. How do i do this also, does it just pull off or has to be cut off etc?

if the ignition coil cable can be increased, any help on how to do this will also help. im mechanical not electrical, but i do know bits and bobs.

Thanks, any help appreciated .

Tyler.b

[Kickstart]

Hi

Depends on the coil. On some coils the HT leads screw into the coil (effectively the coil has a self tapping screw coming out onto which the lead screws, just screwing into the copper centre wires of the lead).

However some are moulded into the coil. For an aftermarket one I would guess it is probably a separate lead.

All the best

Keith
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[tyler_jrn]

[Kickstart]

Hi

No problem. You can possibly extend the lead, joining an extra length on but this would be a last resort for me (I wouldn't trust such an extra joint to be as waterproof).

Think some bike coils might use a push fit lead (like silicone leads on cars), but none I have used.

All the best

Keith
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Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[WD Forte]

I dont like using HT 'joiners' much either
but if you have to, I'd suggest using heat shrink sleeving over it.
Apart from keeping moisture out it gives a bit of extra
mechanical protection and insulation as well
I get all mine from Ebay.

As regards HT leads.
Apart from Ebay a local mower repair shop will probably sell you
copper cored HT lead as cheap as anybody and plug caps as well
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bikers smell of wee

[Vincent]

Any way of mounting the coil nearer the cylinder head?
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Space Is Deep

[tyler_jrn]

Hi, Thanks for the help guys. with a little searching found a nice branded CDI and Ignition coil which the wire is screwed into the coil so if needed it can be exchanged for a longer wire. I ordered 1m of wire for a few £ and a new ngk spark plug cap too.

Hopefully my bike will be sorted now, should be arriving tomorrow so ill let you guys know. The new coil has a better more voltage spark so it should be better for starting on cold days and at high rpms, the cdi has better timing, and timing advance. I must have to turn it on 10-20 times before it will stay on, or sit and rev it for 30 seconds. It starts up fine at say 600rpm then it will get lower and lower and lower and then turn off after say 4-5 seconds each time. once warmed it doesn't stall it just drops power every so often, surges around mainly in 4-5th gear. but sometimes its been bad enough it wouldn't rev from 3th to 4th because it just kept slowing down. Some days its fine and because off this i suspected an electrical problem, battery's fine. next things are to change the cdi and coil and hopefully there will be some improvement.

I also noticed the spark on the plug was orange, i believe a common symptom of a bad/breaking coil. Hopefully it will run better with these new parts!

Thanks again guys!

Tyler.b