Tighten the slipper right up, like really tight, get someone to hold both rear wheels firmly and blip the throttle, if it wheelies then it was the slipper, if it slips then its the diff. Crude and probably the wrong way but it definately works
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Canon 40D (350D backup) - EF-S 18-55 - EF-S 17-85 - EF 100-300 - EF 50 - Canon 430 EX || Speedlite - Canon BG-E2N Grip
Adobe Photoshop CS4 Extended
AX-10 Crawler - Thats all I have left!!!