Set the duration to around 0.7 sec and the bike is alot more responsive to the throttle, wheelies are easier to hoist and control. Thanks guy's. Funny thing is nobody around my area had heard of it, even MX'ers, I wondered whether it was applicable to a Australian spec WR but figured if I measured factory duration ( 1.7 sec ) it could be reversed if it did'nt work. Beware the removable flat slide can be installed upside if it falls off while checking you're needle clip, yes I'm from a 2 stroke back ground so used to 1 piece slides. Thanks again.