No Spark, Please Save Me

I have recently purchased a garage kept, 1978 Kz650-B2. I am a relative newbie when it comes to bike mechanic/electrical but I wanted to learn some new stuff so here we are.

When I got the bike the owner had given up on working on the bike as a project but it was pretty good condition for its age. He claimed the stator was burnt and needed to be replaced and the bike would start up, sounded suspicious but I didn't care and I got the bike anyway. Replaced the stator immediately and the bike didn't start up. Push to start had the engine rotating but I found the ignition coils were fried.

Since then I have done quite a bit of work on this bike but have failed to get her started up. I am fiending to ride this thing so hopefully one of you could possibly give me some insight into what I could check out to determine what I need to work on to get this thing running again!

First thing I did was change the oil, clean out the carburetors, gas tank, and petcock. New ignition coils, new battery, new stator, and several new fuses as the bike only came with the original 20a fuse and was missing the other 2 10a fuses. The bike still has its original contact breaker points, the surfaces are slightly rough but I set the gap nonetheless and set the timing as well. The points spark when I try to start the bike so they aren't completely useless yet.

I tested out the ignition coils again to see if I am getting a spark to the spark plugs but I got nothing using the classic screwdriver in the plug boot test. What else should I check out, rectifier/regulator? The fuses have been rewired as well to support car fuses so perhaps there is an issue in that region still. If anyone has any info to offer me it would be greatly appreciated. Thanks

Hi, have you tried putting the spark plugs in the lead and checking if any cylinders have a spark? If two cylinders spark and two don’t, it could be a dodgy coil.
I’d separate any bullet connectors, crimps and electrical connectors to check for corrosion and give them all a good clean, sounds minor but poor connections can all add up.
Are the spark plugs wet when you remove them after trying to start?
Is the fuel new?
Good luck!

Do you have an electrical multimeter? An inexpensive one will do for basic diagnosis, but if you like nice tools, get a nice one. As uncle nick mentioned, it could be fuel or electrical, a combination of the two, or even mechanical. With a neglected former project, nothing is off the list of possibilities.

That being said, it is best to start with the basics. Are the spark plug leads (secondary wires) connected to the proper spark plugs? One coil fires cylinders 1 & 4, the other one fires 2 & 3. Is the kill switch set to Run?
Are the coils getting sufficient voltage? They should get within 0.5v of full battery voltage. The battery should measure 12.5 to 13 at rest with nothing on. If the coils are getting low voltage, there is likely corrosion in the connections of that circuit. A dedicated elelctrical contact cleaner like Deoxit will work wonders. Do not use WD40 or dielectric grease.
If the coils are getting no voltage, there may be something disconnected, or there may be a problem in one of the switches. The contacts in the switches can get diverts and corroded, and solder gets brittle with age, so a soldered connection may have come undone.
The factory service manual has some good diagnostics in it, and it will tell you exactly what sort of readings to expect.
There are several members here that have forgotten more about this than I will ever know. I suspect one or two of them will be along directly.
If the points are arching, the condenser may be shot.

It was figured out in a different post last week.
But it's interesting to hear your ideas on what may have been wrong.
www.kzrider.com/forum/forum-index/4-elec...-spark-still?start=0