There's really only one rule to remember about extended warranties. This is - forget the extended warranty.
They are just another method for the dealer to screw more money from you by playing on your fears.
Ask yourself - how much in repairs would I expect to pay in the period covered by the warranty? I GUARANTEE you it will be significantly less than the cost of the warranty - bound to be - the dealer has thin information already, and he's not going to lose. Take into account the time value of money (a dollar paid today is worth a lot more than a dollar repaid tomorrow, because of risk and uncertainty) and the whole thing becomes a crock.
Offer the dealer this deal. You pay me the cost of this warranty, and I'll pay it back in a few years, -100%. Will he take it? Nah.....!
An extended warranty is a real good deal - for the motorcycle dealership. It's very expensive and may or may not give you the protection and peace of mind you are looking for. If you do want one, it probably would be best to pass on the dealerships offer and search the net for the best value. Read the policy carefully to make sure that you get the coverage you want at a price you're comfortable with.