TOPIC:

Need to buy coils for KZ900 stock with Dyna S ignition, is there any advantage to going with Dyna 3 ohm coils over the ones Z1Parts or Z1 Enterprise sell ?

The Dyna coils are higher output - Approx 35,000 volts.
They are more able to sustain a strong reliable spark at higher RPM/'s and cylinder pressures which results in a fuller burn and more power.
The difference in ease of starting and overall running is noticable over the stock coils..

 

zed1015 wrote:

The Dyna coils are higher output - Approx 35,000 volts.
They are more able to sustain a strong reliable spark at higher RPM/'s and cylinder pressures which results in a fuller burn and more power.
The difference in ease of starting and overall running is noticable over the stock coils..

Ok thanks, any fitment problems? They look entirely different.

The green coils fit perfectly.

mvent wrote:

Ok thanks, any fitment problems? They look entirely different.

The Dyna coils bolt straight on BUT the stock coil spacers may need packing up with a couple of washers or longer ones using.
It's possible for the Dyna coil body to hit the mounting bracket before the mounting bolts are fully tightened which causes the laminated steel core to flex and eventually the insulation will crack leading to premature failure.
Also orientate the coil towers facing forward to allow the leads to comfortably clear the frame and be wary of the mounting post closest to the LT connections touching the terminal screw as they are very close and the mounting post may need insulating or narrowing to prevent them shorting.

I used some nylon tube type spacers found at the hardware store to replace the metal spacers.  They are 1/4" ID and 3/4" to 1" long.

Yes use nylon support spacers or heat shrink the stock metal ones and add 3-4 6mm and longer bolts washers for proper height. I run the Dyna S system with green coils on all my bikes. I have never had an issue.

What they said.

When I switched to an all-Dyna setup (including plug wires), I did the ol' hold a live spark plug near a cooling fin and touch the starter to check for a spark trick—I was (figuratively) shocked. Never before had I seen such a fat spark from a spark plug. It has really made a difference.

Ditto what they said. I simply bought 4 1" long spacers from Ace and ground 2 of them on the side to create a "flat" spot so the nylon spacers wouldn't interfere with the LT screws. Worked perfect and yes, longer screws are needed. 

The coils I got in my Dyna S kit are marked 5.0 Ohms, fwiw.

That setup should work fine.  And with the relay you added, the ignition will be trouble free.