KZ440 LTD Build

Since your bike has points, have you checked them?  

Test the ignition coil first for it being in the roughly right range for resistance on the primary and seconday winding. Old coils can fail when they get hot, for sure. I'm using a replacement coil because I have to. I think replacement coils are garbage btw. Maybe they work but for how long - who knows. Did you check for battery voltage though? 12.6+ volts is healthy. When you start the bike, the starter motor's draw will drop this a lot at the input to the coil. but it should immediately come back up when the bike starts. It needs a lot of voltage to collapse the EM field and produce a spark. If you're testing this, check also that your points spring is isolated from the bike's ground, and that the input to the coil is likewise not shorting to ground. 
Regarding aftermarket parts in general: they are what will eventually terminate these bikes. Everything from fake spark plugs to coils that don't work, etc. 

Michi wrote:

Test the ignition coil first for it being in the roughly right range for resistance on the primary and seconday winding. Old coils can fail when they get hot, for sure. I'm using a replacement coil because I have to. I think replacement coils are garbage btw. Maybe they work but for how long - who knows. Did you check for battery voltage though? 12.6+ volts is healthy. When you start the bike, the starter motor's draw will drop this a lot (approx 10.0v) at the input to the coil. but it should immediately come back up when the bike starts. It needs a lot of voltage to collapse the EM field and produce a spark (the EM field is collapsed by breaking the ground - the input voltage will simply determine the HT voltage as a ratio). If you're testing this, check also that your points spring is isolated from the bike's ground, and that the input to the coil is likewise not shorting to ground. 
Regarding aftermarket parts in general: they are what will eventually terminate these bikes. Everything from fake spark plugs to coils that don't work, etc. 

To be honest I think the exact opposite, in many cases "aftermarket" parts are what are keeping these bikes on the road with many OEM parts now obsolete. There is however "aftermarket" and then there is "oriental aftermarket" (and not even all of that is garbage, it's just a lottery as to which is)

Wookie58 wrote:

(the EM field is collapsed by breaking the ground - the input voltage will simply determine the HT voltage as a ratio). 

Yes I know - the point I was trying to urge was making sure there is enough primary voltage there so that the multiplied-up voltage at the spark plug is sufficient to create a good spark.

Hi all,

Thanks for the responses. I did verify the dwell gap on the points and verify that the spring has no continuity with ground when it’s not touching the contact breaker points. The contact itself is certainly worn but not bad enough to affect anything I think. 

The preinstalled Nippon Denso 029700 ignition coil (from a GS750?) has resistances across the coils that are in the expected range when cold. The battery is fine as well. 

 

Update:

I ended up replacing the ignition coil, spark plug boots, condenser, points contactor, and spark plugs. After replacing the ignition coil and spark plug boots, I noticed that the spark was substantially stronger than before.

It took me a while to figure out how to rewire the contactor, but eventually I got it running. For anyone's reference, it can go (top -> bottom) with the nut, locking washer, washer, isolator #1, contactor base plate hole, isolator #2, leaf spring, condenser lead, wire to ignition coil, washer, and bolt head. I'm not sure if that's necessarily the correct order, but it works as far as I can tell.

After verifying spark and reassembling, I injected some fuel into the carbs and tried getting it going. It started up easily enough but was knocking (?) horribly on one cylinder during that first start up. I quickly shut it off and tried restarting it a moment or two later. No knocking was present on the second start, and it was running significantly better than it did before all of this work. I'm choosing to ignore the knocking or whatever that horrible sound was as long as it doesn't come back. I shouldn't, but eh it's probably fine for now.

Tonight, I get to deal with reinstalling the gas tank and taking it for a test drive to verify the original issue with dying while hot is gone. 

I'll end up posting here again when the bike inevitably breaks down again in the next month or whenever I care enough to fix the speedo. Cheers all. 

We look foreword to the ride report.

Hi all, 

I’ve been busy so I haven’t had a chance to look at the bike until yesterday. I fired it up again with a syringe of fuel and decided I was hearing some knocking still at idle. To check the timing, I picked up an analog multimeter today, and hooked it up tonight. Holy cow, the (static) timing was retarded by a *lot*! I’m amazed it fired up at all.

I tried adjusting the timing, but the best I can get it is a hair past the crankshaft timing mark (T; not F). My understanding of the best way to fix this, is to adjust the points contacts to get the correct timing set rather than just expanding the screw slots on the disk. I’ll play around with this Friday and will just dremel out the screw holes if I can’t get that to work.

should I fail to make any difference with adjusting the contacts, how bad is it to run the engine with the static ignition timing set to T? I’m assuming the engine will be perpetually down on power, but it should be capable of running acceptably right? 

Yes, turn the crank to get the F mark under the notch, then loosen the backing plate and set it to roughly the middle of its adjustment zone, then loosen the points screws so that the points module slides around on the backing plate, and tighten them down again so that the points spring is pressing against the cam lobe but still closed. Tighten down the points backing plate and the points screws. You should be in the right sort of place now to begin adjustments. Turn the crank 360 degrees and you should be either bang on F or just a little to the right or left. Adjust the points backing plate as necessary and turn it 360 degrees and check again. Once it's correct, turn it to open the points at maximum and check the points gap. If it isn't correct loosen one points screw and try to set it right. Spray it with electrical cleaner, turn it 360 degrees and check both gap and firing point again.
You may have to repeat this process a few times before it's all correct.