Take the 2-speed out and sell it on ebay. A buggy is not a buggy without a centre differential. I'm afraid I can't help you with the problem, as even though I had a Hyper 7, I would never have considered putting a 2 speed in it, therefore I've never even seen the unit.

Centre diffs rule, and the 2 speed does nothing for you I promise. Maybe give you slightly better acceleration, which should always good with a decent torquey engine anyway. Honestly, put the centre diff back in, and if you're looking for more top speed, just gear it up a bit.