It very difficult to debug an intermittent problem.
I you think it might be the ECM, the logical thing would be to get another one, new or used, and see if the problem stops.
I dont think the ECM warms up very much when the bike is running... maybe.. depending on where it is on the bike. If the problem only happens when the bike is warmed up, then maybe you could either heat up the ECM with a heat gun and see if it runs rough right when you start it
or maybe somehow wrap it with an ice pack to keep it cool, or find a way to heat shield it with aluminum foil... ?
If there is a burnt smell by the connector look at the pins carefully and see if any look overheated, corroded or burnt. It could be as simple as a bad connection on one of the pins, because all the pins on the ECM are necessary for the bike to function 100%. Sometimes unplugging a connector and plugging it back in several times is enough to wipe the pins off and clear away corrosion.
Last edited by KCW; 05-09-2019 at 09:13 PM.