Thanks for posting the videos LJH. Good to see full documentation of an issue most of us have struggled with from time to time, in various degrees of pain.

For reference, I had the honor of riding LJH's JH600 (2-wheel) a few months back thru the mountains of Beijing, and LJH was riding the JB600 2-up. The JH turned the odometer at 5,000km that day, and the B was somewhere close to that mark I recall. Both bikes performed amazingly well. Not a stall between them on the 200km ride under blue skies.



It's sad to see the change in behavior from just a few months ago. So yes. the JH's aren't born this way, but some have developed these symptoms with a mysterious cause.

My JH stall issue worsened around 10,000km when there was excessive heat ultimately resulting in a fried stator. The stator was replaced and the stalls were then few and far between (during the Inner Mongolia Ride). Then about 1,000km later I was getting frequent stalls (same type as LJH captured in the videos) - usually occuring when slowing down, and the RPMs are winding down thru the gears, like when approaching an intersection! [dangerous]. After tweaking my idle higher, I'm now only getting the occasional stalls, which is still hen mafan!

Couple of questions/comments:
- I also get the 15s stall after starting up from cold
- My exhaust header also gets red hot when first starting
- You mentioned the JB's idle speed is about 1700, where's the idle with the JH?
- When the the engine actually stalls, where is the RPM at? Is it stalling at the same RPM each time?