JohnT, I did this to mine - an NZ/Aust spec bike which I assume is closer to the Canadian spec than the US spec machines. Does yours have a single piece stainless muffler with non-removable end cap?
Whereas with the WR timing the bike needed to be revved to the moon to get maximum power and lacked in the lower to mid range, with the YZ timing the good usable power comes in much earlier and the lower to mid rev power is much greater. It becomes more of a mid range "grunter" with the YZ timing, allowing a higher gear to be used than with the WR timing in many offroad terrain conditions.
Absolute top end is about the same but "average power" through the WR gear ratios is much better.
Having experienced both timing setups on my bike, there is no doubt that this engine was always designed to use YZ timing and that WR timing was a compromise for the greater backpressure the stock WR exhaust would exert.
I had to go up two jet sizes when using YZ timing and a free flow exhaust is strongly recommended. I would recommend the YZ timing procedure unreservedly!