ALL the crank specs are in the Tech pages, where you obviously didnt look yesterday when talking about the puller. I think you are a prime candidate for subscribing to the new Members section (http://members.nsr-world.com) when it opens , as there is going to be a full English Workshop Manual on there which will be near idiot proof!

Yes the main bearing will need to be replaced as like you said its possible for it to spin. This will then damage the crankcase its self. Well worth changing while you have its stripped down.
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If I have to take the carbs off once more...