Coils ? Dyna's or Standard

[Tonto]

Chaps advice please: having some issues (as always) with my A4 (sometimes I know my bike hates me) and might have to replace the coils. Was unsure whether to fit some new standard units (from Uncle Dave), or push the boat out and go for a set of Dyna's

My bike rarely gets thrashed or does big mileage so was wondering, from experience, can anyone vouch that Dyna's are much better and worth the cash premium ??

Cheers Tim

[Pigford]

Dyna coils - hands down every time

[Charlie]

I am another Dyna coil/ignition user - it gives me a much fatter and stronger spark than the tired originals could manage.

[Vendetta761]

I am also after a set for my ST rebuild, can anyone recommend the best source for a set please?

[Ginger Bear]

I had a new pair of green dyna's delivered for £85 last year from Z1 Enterprises.

[Charlie]

Mine came from Dave at Z Power

[zed1015]

Get them from z1enterprises or pitstop performance.
Much cheaper than buying from the uk.
You will save around a 1/3rd even with shipping and customs.

[paulmceleney]

There is no difference in performance had them on my bike when they packed up, PUT standard coil back on and could not tell the difference so save your money and buy standard it will start easier with dyna coils and there is a bigger spark

[Jeff Saunders]

Chaps advice please: having some issues (as always) with my A4 (sometimes I know my bike hates me) and might have to replace the coils. Was unsure whether to fit some new standard units (from Uncle Dave), or push the boat out and go for a set of Dyna's

My bike rarely gets thrashed or does big mileage so was wondering, from experience, can anyone vouch that Dyna's are much better and worth the cash premium ??

Cheers Tim

Why do you think you need new coils? What problem are you trying to solve?

Before you replace any coil, there are some simple things to do that may save you buying coils.

1) check the voltage at the coils. Normally a fully charged battery will show over 12.5v across the battery terminals. With the tank off the bike, insert a probe into the yellow/red wire that splits to feed both coils. Put the other probe back to the battery negative. You won't get 12.5v - but you need at least 11.5 volts to get an effective spark from any coils (new or old). If under 11.5v, pull apart all the connecter blocks, bullet connects and clean them - it's difficult to clean the ignition switch and kill switch contacts - but sweeping the switch from side-to-side will often clean the contact.

2) check the resistance of the coils - you want roughly 3.7 ohm to 4.2 ohm on the input side, and with the plug caps removed, roughly 15,000 ohm between the two h/t leads. The key here is getting very similar readings from both coils. While checking the h/t side, wiggle the wires around - often there are breaks in the h/t and a static test doesn't always show this. If the readings are bad, it is time to replace the coils, if the readings are good, it doesn't necessarily mean the coils are good - but at least a decent chance they are.

3) remove the old plug caps and cut 1/4" off the ends of the h/t leads - thread the caps back on the leads

Unfortunately the original coils have the h/t leads molded into the coils - and often it is these that give all the grief... not much you can do if they are bad

The Dyna coils have replaceable h/t leads - over time this is a plus.

[kev edwards]

Had both on my bikes and it made no difference at all, but the main thing is to make sure your wiring is giving the coils what they need to produce the spark to start with.

[Tonto]

Thanks for the responses guys.
Jeff, thanks I'll carryout the tests you suggested (today I fitted new plugs, plug caps and trimmed the HT leads): current problem I have is an intermittent misfire or zero running on number 3 pot: I have compression, my carbs were recently checked over, set up and balanced, and whenever I visually check I am getting a spark.
Real frustrating, as one day she runs fine and the next when she decides not to play ball ! e.g Today she struck up first touch of the button and ran perfectly.

[Pigford]

Check the KILL SWITCH


The power to ignition goes all the way to the kill & back

[Jeff Saunders]

If only 1 cylinder drops, I suspect the h/t leads or the plug caps.