Won't start

Hey guys, long term lurker but finally made myself a profile and I'm afraid I need your help! I've recently acquired a 1980 kz440. It won't start. When I got it it had cheap horrible Chinese pit bike carbs on so it would just about run but didn't like it, I sent off and had some mikuni's delivered but all took a while and life got in the way so it sat for a few months. Fitted the carbs, charged the battery and tried to get her going to no avail. The aftermarket ignition (again, cheap Chinese crap..) had disintegrated so I fitted another ignition switch and it turns over lovely and fast, still no start! So plugs out, no spark. Check points, adjusted and it ran for maybe 10 seconds and died, but they were pitted, so I bought new points and condenser, got spark but no running! Then lost spark. Coil was reading high Ohms so to rule it out put a new one on but no change. Points gap is correct, and I gave them a clean to make sure. So as it stands I have no spark, however a few times I've check something, undone something, maybe just sworn at it a bit and I'll get a spark for a few seconds, at one point I had spark on one cylinder but not the other. I'm at my wits end and I just need someone with some fresh eyes to point me in the right direction. I've got 11.5 volts to the coil right now, continuity test shows it's earthed when points close, points gap of roughly a playing card (seem to have misplaced my gauges).

Read through this posting

www.kzrider.com/forum/4-electrical/61368...-kz440a1-with-points

Ah perfect, thank you. That gives me a good list of things to go over, I did do a search but finding the same thing is like finding a needle in a haystack! I'll get some of those tests done tomorrow and will report back!

Right so I ran through the tests from that post -
Battery is reading 11.95 (have been cranking a fair amount to try to diagnose).
Points closed.
Battery to coil positive is 10.88 when charging, 11.92 unplugged.
Battery to negative on coil is 0.13.
Points open.
Battery to positive on coil 11.91
Battery to negative on coil 11.90.

Voltage drop test shows 0.1 in the left and 0.0 on the right.

Where do I go now?

Charge the battery. Ed

I'll top it up but certainly not the source of the issue!

Jackasaurus wrote: I'll top it up but certainly not the source of the issue!

I agree, but even if you correct the actual source of the issue starting the bike with a battery that is charged to less than 12v will be a problem. Ed

The motorcycle needs a good fully charged battery to start & run right. Every Kawasaki service manual says to make sure the battery is good before trying to diagnose any problems. I would put the battery on a good motorcycle smart charger overnight, then do a load test. After charging, the battery should be at least 12.6 VDC, but a good battery will be higher. High beam load test (engine off): after charging & verifying at least 12.6 VDC, turn the ignition switch to ON w headlight on high beam >> the voltage should drop to about 12.2 VDC. If it drops below that, the battery may need replacing. If it drops below 11 VDC, the battery is probably shot. I use a Ctek US 0.8 smart charger & VC97 digital multimeter.

Okay, I think I've found something! So went to double check static timing and both sides of the points were earthed out, currently chasing it back, positive on the coil seems to be earthen so time to pull apart the wiring and find out what's going on!

If the ignition was off, it's expected for both sides of the points to be earthed. The ignition and kill switches short the coils to ground, so setting static timing with the ignition off will result in the meter reading the coil voltage with points open. You can disconnect the coil from the points to eliminate this and set static timing, or watch the resistance spike from coil resistance to infinity to check timing.

There should be no continuity between the points with the points open and the ignition and killswitch on.

Jackasaurus wrote: Okay, I think I've found something! So went to double check static timing and both sides of the points were earthed out, currently chasing it back, positive on the coil seems to be earthen so time to pull apart the wiring and find out what's going on!

Jack,
Did you find 0 volts on the positive side of the coil?
For this to be valid:

Meter on DC V
black probe on negative battery post
red probe on positive coil terminal
Ignition must be on/engine off
All connections connected
Points closed

If this is the case, you have a break in your positve 12v line to the coil positive terminal.
But all of the above has to happen. Ignition must be on like Gavroyer said.

gavroyer wrote: If the ignition was off, it's expected for both sides of the points to be earthed. The ignition and kill switches short the coils to ground.

Nope!