Ignition Coils

While the Dyna S is pretty pricey at around $125,, they will work with stock or any aftermarket coils. AFA a hotter spark, that is coil dependent, not points/igniter dependent. Dyna coils do produce a hotter spark than stock coils.So do the Accel coils I have on my GPz.
I think I paid around $125 for the coil/wires kit, and the wires were suppression type, so I did not need the expensive NGK suppression spark plug caps.

koolaid_kid wrote: While the Dyna S is pretty pricey at around $125,, they will work with stock or any aftermarket coils.

Depends who you ask. If you use a four Ohm stock OEM coil in an ignition designed for 2.7 - 3 Ohms, it reduces the energy stored in the coil which is given by:

e = 1/2 L (I) squared

where L is the inductance of the coil (which is actually a flyback transformer)

since energy is current squared, increasing the resistance (which reduces current) does reduce energy.

As to whether increasing spark energy above stock amount results in better performance, I tend to doubt it but a more accurate advance curve might. Anyway, I think a 4 Ohm coil would work fine with a Dyna but they do recommend 3 Ohms.

Sure it reduces energy, I agreed with you in an earlier post. However, it will still work,which was my point.
In fact, the OP could use a set of used OEM coils from a bike that has electronic ignition and save some money, I probably have a set lying around, also.

After talking with my Dad's mechanic, the coils should still be fine as the bike started up fine about a month ago before I took the carbs off to clean them up. Since that is the case I am just going to clean up the connection from the wire to the boot by trimming it down.

Even if they do still work, is it a common modification to replace the coils on these bikes that are 30+ years old? Might be something I look into before winter is over depending on where my budget is...

Dyna 3 ohm, and Accel 3ohm coils are a popular replacement, but watch how close both of these coils primary connections are to the mounting spacers, possibly, causing a short circuit. Replace this spacer with one made of Nylon, or plastic.

oredigger wrote: Even if they do still work, is it a common modification to replace the coils on these bikes that are 30+ years old? Might be something I look into before winter is over depending on where my budget is...

Yes, it's highly advisable.

MFolks wrote: Dyna 3 ohm, and Accel 3ohm coils are a popular replacement, but watch how close both of these coils primary connections are to the mounting spacers, possibly, causing a short circuit. Replace this spacer with one made of Nylon, or plastic.

I put the Dyna coils on my GS1100E and Accels on my GPz. Both are great, although the Dynas were a bit more expensive because they did not come with the wires, which cost me another $20.. I highly recommend that you go with resistor wires, which removes the requirement for the expensive resistor caps.
AFA the posts, I used liquid electrical tape to cover the terrminals once they were finished., just to be sure.