Checking compression and spark with Dyna S

In the next few weeks I will be installing a new set of Dyna coils, copper wires and a Dyna S on a 78 KZ650. Also I will be checking comp a number of times and the spark to the plugs since either my points, 30 year old coils or wires gave up on me.

I'm ok with the installation and the right way to check comp but am worried about (Protecting !!) the coils and the dyna while checking spark and comp. To check the spark I would pull the plugs fit them into the wires and lay all 4 on them on the fins of the head and crank it over. Is this ok? ..... I've read several times of people damaging the electronic ign or the coils by shorting them out and don't want this to happen !!

Also to check compression I usually pull all 4 plugs and drape the plug wires over the valve cover and crank it over to check comp. This is fine right? Maybe I'm worrying about nothing since I've done this a fair amount of times over the years but after the cash I've spent on the top end rebuild and now the ignition set up I can't afford to fry anything now.

It's ok to short out the high-tension leads (sparkplugs etc). It's bad to leave them in a position where the spark can't complete the path. That will pop a coil or ignition system. Just make sure all four plugs are on the motor so the spark can get to the engine.

For a compression test, it would be even better to disconnect the power lead from the coils. It's the red or yellow or yellow/red wire going to both coils.

Finally, just so you are aware, the 78 and 79 KZ650's have a single-phase charging system. These systems don't produce as much power as the earlier and later 3-phase systems. The Dyna S ignition system uses much more power than the stock system. Sometimes this will lead to the battery getting low at idle etc. Keep an eye out for that. You can always convert it to a 3-phase later if necessary.

your bike has a kicker right use that and keep your ignition off hold your throttle wide open and kick it until the gauge quits moving. I have had problems using copper core wires with electronic components before so I use carbon core suppression wires instead now.

Exc answers to my questions........ Its appreciated. Picked up a in line spark tester too to check the spark from harbor freight, a tool I had forgot about.

I have blown up a Dyna module checking compression, so I learned the hard way to protect the system. I simply disconnect the power wire to the coils.