Depends what engine you have as to how detailed the service will be.
The degree is the pitch of the prop. Again depends on what engine you have but generally you can alter the pitch to alter the performance of the engine. Normally the higher the pitch the higher the revs (which has a limit). Get it right and your motor can pull more (torque), go faster, quicker to the place, save fuel etc. Get it wrong and your engine can go bang!
More detail from you will determine what advice is given.
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