Looks like this is a design flaw that still hasn't been addressed, which is a little disappointing.
My wife and I just got back from our first over-nighter on our 2018 Roadmaster. We got stuck in traffic between Pigeon Forge and Gatlinburg. This being my first air/oil cooled motorcycle of note, I didn't have a good feel for what the engine could take heat-wise. The check engine light came on while in the traffic, so I pulled over at the next opportunity, suspecting that it was trying to tell me that the engine was overheating or something. Instead, it was the knock sensor low voltage code. I let the bike cool down for about 15 minutes, and tried to restart, but no dice. I figure it must have been a little vapor locked at this point. Another 10 minutes of cool down and it fired up fine, but the code was still there and the throttle response was definitely weak (which I later learned was because the ECU retarded the timing to protect against knock-induced damage).
The next morning, after the bike cooled off, the code was still there. We proceeded to a dealer in Waynesville, NC, where we had to wait our turn for 2.5 hrs for them to look at the bike. They found the front cylinder's knock sensor had laid against the cylinder cooling fin and melted through the insulation, shorting the wire against the cylinder, which threw the code. They didn't have a replacement part on hand, so they zip tied it up to prevent further contact/shorting against the engine and all has been fine since then.
I'll be scheduling an appointment with my local dealer to get a proper fix, and making sure I approve the results before they button the bike back up.
-SR-
