My dealer really took time to figure out the problem and could tell after a lot of software/hardware settings that it has to be the built up oil in the map sensor. So cleaning it seems to be valid point. That the failure starts after the first service could be just coincidence. Mine started way later with stalling at around 6500km and I'm currently slightly above 10k.
I'll see how it goes this year once the season starts...
Chiming into this thread to share that my Trident has had the same problem. For context, I've had my bike for about two years and I ride the sh#t out of it. It's a daily commuter for me and I've put 12,000+ miles on it since I bought it brand new. Unless there's ice or snow on the roads, I ride it everyday and I really gotta say I love this bike. It's been amazing until the dreaded stalling issue appeared.
The stalling began 4-5 months ago (I think) as a very occasional occurrence and in the same way that everyone else has been describing. Maybe once every few weeks. It happened so infrequently that at first I thought I was causing it by doing something wrong. My bike would start right back up, so I didn't really think much of it. But as time went on, it became more and more frequent. At least, once per ride. Last December, I took my Trident in for its annual service and mentioned the stalling to the technician. He said they would take a look at it and see what's up. When I picked up my bike, they said that they did not experience any stalling during their test ride after the service. Because they were not able to replicate the issue, no work was done. But they said to bring it back if the problem continues.
The problem continued....
Fast forward to the beginning of January and it was happening several times in a single ride. On a bad day, it would stall at every light or stop sign I'd hit, making the bike feel virtually unrideable. Then I started experiencing some trouble starting my bike when the engine was cold. I'd pull in the clutch, hit the ignition switch, and the engine would turn over before promptly dying. So I took it back to the dealer and this time they reflashed the ECU, thinking there might be some kind of bug there. I rode the bike home and, as you can probably guess, the stalling persisted.
I returned to the dealer a couple days ago and shared this thread with them, saying that it might be worthwhile looking into the MAP sensor. They just called me today and said that the MAP sensor and the MAP sensor hose was mucked up with oil and that there was also oil inside the airbox. So they cleaned the airbox out and replaced the sensor and hose. They said that the stalling issue has since been resolved. I asked if this would be a one time fix or if replacing the MAP sensor would be a normal part of maintaining the bike. They said, truthfully, they didn't know as this is an issue they hadn't seen before.
I'll be picking up my bike in the next day or so. I'll circle back here if anything changes. Just thought I'd share my experience. If you're bike is stalling, it's most likely the MAP sensor and hose.
I guess we'll all have to wait and see if this will be a recurring issue....