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Hey guys,

My 1978 KZ650 SR is coming along. I've rebuilt the carbs and installed them, the bike starts and eventually runs satisfactorily. By eventually I mean cylinders one and two get the bike running and then eventually three and four join the parade. Now that's just plain weird seeing as how one and four use one ignition circuit and two and three use the other. After some judicial use of an inductive timing light, I've figured out that the coil wires for three and four just aren't cutting it. I also tested the coils. I get 4.2 and 4.4 ohms for the primary (Clymers says 4.0), 30 something for the secondary on one of them and 14 on the other. Clymers says 23 ohms. That says to me that the coils are bad. So I'm thinking the best thing to do is replace the ignition system with a Dyna S along with coils and wires. Z1 has them and I like doing business with them so I'd like to buy them from them. The only problem is that the highest resistance of any of the coils listed for use with the Dyna S is 3 ohms. The web site makes a point of telling us that littler is not good so I'm wondering what to do.
Anybody else ever run into this?

Thanks!

I could be wrong but as far as I know the 650's use 3 ohm coils. I have a Dyna S with Andrews 3 ohm coils.

Just checked my FSM and coils should test out to "about" 4 ohms, mine runs great with 3 ohm coils. Now I'm worried...

Is battery fully up to snuff?

The battery question is a good one .. 12.4v by my multimeter's calculations.

Taking a cue from another post, I clipped wires to three and four ... four now works as well as one and two. Still fiddling with three.

Should check specs per FSM, but am thinking battery should measure 14-15 volts across the terminals at 5000 rpm.

Sometimes cranking a cold engine with the electric starter pulls an already marginal battery down enough so that the ignition is weaker, for a while at least, which causes a plug to load up. The plug may or may not later begin firing. If feasible, it may be better to use the kick starter for initial cold crank-up, thereby helping preserve the battery. In a pinch, I have run a few miles with the headlight turned off until a missing plug begins firing.

Am very well-pleased running Dyna everything from Z1E on both my Z1 and KZ900.

Good Luck!

Dyna-s runs great on the 77 650 c1...