This document, courtesy of the Guzzitech forum explains how to clean it and prevent it happening again.
Rediculous, these circuit boards are crying out for PCB lacquer at the very least. Even in the comparative ‘safety’ of a car dashboard you can still have the odd problems with condensation and water leaks, this is not good enough for a bike. Unless you have a centrally heated garage and only go out on it when the sun shines.
The problem is that moisture can build up, and there is no drain hole, so the pcb is sitting in a pool of water. Even laquer won’t hold up in those conditions.However, it’s not that common, so the sky is not about to fall.
That’s a lot of misting up to be creating pools of water! Must be getting in from outside somehow. This is what I mean such things need to be better sealed.
Here’s a link to a little more info for those wanting to drill drainage holes: http://forum.guzzitech.com/forum/216/1892?start=30