A spacer will improve the belt to tyre clearance but will make the belt run hard up against the bevel box sprocket guide plate. This will eventually fracture the guide plate attachment screws. You cannot adjust the swing arm further as you run out of adjustment with the left pivot hitting the bevel box sprocket before it and the wheel sprocket are aligned. The problems all originate from the system being designed to run with a narrower 1" drive belt that proved not to be up to the job I think.
