Hi all, new to the shack, just bought a 2nd hand Speedfight 4 on a 69 plate, 1400 miles for my commute which is 2 mile 4 times a week. I have a problem where the bike sometimes won’t start and battery sounds flat, but then I can leave it a day and it will start. Not sure if the batteries getting a proper charge. Anyway a dealer has suggested a modification to enable the battery to charge at low revs and speed. Has anyone had this done ? And know what the cost is ? Thanks