Greetings:
I'm throwing my 1st official post out there for what hopefully will be some collective wisdom.
It's been 35 years between KZs and I'm excited to get this one going. There is 1 problem I can't seem to properly diagnose.
She starts and idles perfectly and pulls hard right up to 4000 rpms and then begins to stumble and miss above that. You can go WOT to 4K, or attempt to baby it up there, just barely cracking the throttle. Either way, the same result, once you hit that 4K mark, the same stumble happens regardless of throttle position.
Here's everything I've tried so far.
Complete Carb Overhaul
New coils/wires
New plug
New ignition (old one was broken and wasn't getting 12V to the coils)
Checked mechanical timing advance for function
Checked plug boot resistance
Cleaned the kill switch
The only thing that didn't seem right was the resistance of the ignition pickups. When I check the pickups, the resistance starts at around 1,700 ohms and slowly (like over 30 seconds) drops just below 600. That doesn't seem like normal behavior, but it's not a cheap part, so I hate to just keep throwing parts at it.
If anyone has any suggestions, I'd like to hear from you.
Thanks