known bugs ?

[GoldOxide_imp]

Thanks a lot Ferret, is the idle issue immediately apparent when checking out the bike ? or does it show itself only under conditions hard to reproduce ?

I bought my 2013 in September, 2020 with 4525 miles on it, from a private party. It was in beautiful condition and ran perfectly. It had not had any modifications to the engine, like ECU flashing or performance chips or a Power Commander. Within less than 100 miles, the idle problem started. At first, after riding a few miles, when I stopped at a stop sign or traffic signal, it would idle down to 500rpm and, when I twisted the throttle to go, it would die. It would continue to do this until I revved it up and slipped the clutch to get some speed up. It stopped me in the middle of the intersection a couple of times, which is no fun in Phoenix traffic. Drivers here are not forgiving. I don't have exact dates, but before long, the high idle problem started. I would start normally, drive off, but at the first stop, the idle would go to 2000rpm. After the high idle started, the low-idle never returned. From then on, the bike would only idle at 2000rpm. The one exception is that I could dis-connect the Throttle Position Sensor (TPS) and it would run fine and idle at 1100rpm, but would not rev higher than 5000rpm.
I read everything I could find on the Forum about the problem, a lot of it I did not understand. One person claimed to have solved his problem by changing the sparkplug wires and coils. I have a spare set I bought used on EBAY if you want to send me $90 for them. Didn't work. Most others agreed that the Intake Control Valve was at fault. Bought one and had it installed. Didn't work.
To make a very long story shorter, Power Dubs recommended changing out the Electronic Control Unit (ECU). By then I was tired of throwing money at it and didn't want to spend over $700 only to find out it wouldn't work, so I waited. Then a member in South Korea described the same problem and said his Honda mechanic put in a new ECU and the problem went away. So, I decided to try it. I ordered a new replacement from Partzilla for $478, which was over $500 with tax, etc., and installed it myself. The bike runs fine since then. I believe that was in about last September.
The link for the part I bought and installed is:
https://www.partzilla.com/product/honda/38770-MGC-A24
A temporary fix that I found useful was to disconnect the battery leads and connect them together for 15 minutes. Make sure they do not touch the battery terminals during this time. I don't know why it works, but it worked for me. I now have over 6200 fun miles on the bike.
Good luck and I hope this has been useful.

The theory could be the primitive ECU technology when disconnected from its power source is any volatile memory of its run-time parameters are lost and have to be rebulit (or "re-learned") on subsequent rides. The time duration of disconnect might just be to ensure any capacitive storage in the ECU component has had time to drain. Shorting the circuit (with the battery disconnected) helps dissipate any circuit capacitance instantly. Minutes following the short circuit is really not required and is a myth unless volatile memory is supported by a supercapacitor.

So, continuing to use the problem ECU, the parameter building (or "learning") begins again ride-after-rider and supposedly getting more "intelligent" as a reflection of rider's habit or riding style. However, if there is a bug in the ECU firmware logic and/or hardware, then it will eventually show up again without a manufacturer's root cause fix.