I have a 1977 KZ650B1.
It has pod filters, stock exhaust, 105 mains, 15 pilots, air screws roughly 1 1/2 turns out.
I have redone the motor from the base gasket up. All new gaskets/seals, heads off and cleaned in a machine, reset valve clearance to spec, set points and timing, etc. It's all fresh and good. The bike runs/drives GREAT except for a strange issue. Twice in the last 100 miles when I pull up to a stoplight and shut the throttle/pull in the clutch the bike shuts off. I still have lights but it's like I hit the kill switch (which I didn't). I can kick/crank the bike right back on and then it behaves fine, goes right back to the stanard idle speed. But twice it has just dropped to zero rpms and rolled to a stop.
Plugs look great, every mechanical check i can run is OK. Charging systems/outputs all OK.
All i can come up with is maybe my gas cap isn't venting enough when the motor is hot? Or my tank bag is smothering the cap (I carry a lot of stuff)? My local mechanics seem to think i have a fuel starvation issue due to a poor gas cap vent. They say if it was electrical I'd lose my lights and it would be a hard restart. I'm not sure but i'll start here.
