For sure there is a possibility of 300 specific pipes making a difference somewhere, but it's not the be-all and end-all of the problem.

StephenRC45's MC21/300 made 70hp, but it was by no way a standard 300 kit by the time it was making half decent power, and my '21SE would still reel it in if he so much as even slightly over-revved it, due to power not so much tailing off, but more like hitting a brick wall! There was no doubt it was a quick bike, but it was no hot 250!!

Like I say, if you want all new bits, then buy a 300, but if you want a proper motor, build a 250!!
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Andy.
NSR-WORLD.COM

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