Dyna S Coils Any Good?

Need some insight from the experts. I was planning on replacing my original factory coils with new Dyna S coils. But lately I have been reading about various problems with the Dyna S coils on the forum - from cracked housings, shorts, cutting out, etc.

The reason I'm considering new coils is I suspect that I'm not firing consistently as I'm getting some intermittant jerking and clunking on acceleration in all gears. The transmission is fine, chain is fine, wheels aligned properly, rear hub is tight, sprockets not excessively worn and are tight. I have new sparkplug wires, did the WG Repowering Coils mod, went through my entire harness and checked/cleaned connections.

So, my question is: are there other brands out there, or do you recommend staying with Dyna S? I did disassemble the timing advancer per manual and cleaned lubed. I also re-did the connections of new sparkplug wires into the coils, twisting them in rather than pushing as I had when initially installed. That seemed to help a lot, but that jerking/clunking is still there, albeit to a lesser degree.

What do you good folks recommend? Appreciate any and all observations and insights!

Post edited by: Norseman, at: 2007/08/11 22:31

I can only speak from my experience. I have the dyna S ignition with the green 3 ohm coils. Everthing is all good after about 2-3 years.

I would say no worries. The price is good from z1 as well.

Thanks, Austin3119. And yes, I wouldn't buy parts for my bikes anywhere else than Z1, unless they couldn't get a part. Both Jeff and Rob are not only extremely knowledgeable, but always cheerfully ready to help and advise, and their prices are outstanding.

The only thing I didn't notice you mention replacing/checking is the spark plug caps.

If they are the originals, I'd say toss 'em and get a new set (Z1Ent sells them as well) of NGK plug caps.
A set of plug caps is considerably less expensive and quicker to install than a pair of Dyna coils, and you'll eliminate them as being part of the prob.

If you've already replaced them however, you might want to check the condition of the rest of your electrical system components (battery, wire connections, reg/rec, stator, etc) to see if it's all up to snuff before throwing dead presidents at a set of Dyna coils.

And thank you, Retro, and a very valid observation it is, indeed. The reason I say that is I just went through that on my 1981 GS650, and lo and behold, it was the spark plug caps.

In this case, though, the spark plugs are new and the new Dyna spark plug wires came with the caps installed.

Now, I just tested my OEM coils. A clean 12v in (did the WG mod), but both coils resistance tested at exactly 2.0 ohm each, again following WG instructions to the letter (there's another coil thread going that WiredGeorge responded to).

If I understood WG correctly, I should be getting 2.5 to 2.8, so I think I'm on the very low side.

And I also have an odd situation that must have just happened during a short ride last night, as I had just checked my spark plug wires going into the coils prior to the ride. When I removed the gas tank to test the coils, I found the right side coil lying on top of the valve cover! Both "ears" of the mounting bracket had fractured clean through the mounting holes for attaching the bracket to the coil. I've never seen that happen before on a relatively stress-free mount. Really, the only stress is the weight of the coil which is neglible as it hangs almost straight down, and the little vibration of the frame. I just fabricated a replacement bracket from same gauge steel, and baking the paint right now, but I'm still amazed over the failure.

Anyway, if anyone has any input on my coil resistance test coming in at 2.0 ohm, I'd really appreciate your advise!!!

Post edited by: Norseman, at: 2007/08/12 16:41