Couple of places.
Bass Pro sells Mercury and from what I can tell services them too. Never used there services so I don't know how good they are, or cost.
IMHO- this guy is great.
C & M Marine Inc
4002 N Becker Dr, Bartonville, IL 61607
(309) 697-6104
Place is a Morton building packed full of old boat motors/parts. He tuned up my '57 Johnson last year. Couple of my wife's uncles recommended him to me. One man shop, leave a message and he will call you back. He's been in business a long time.
HOI Crappie Club
Where family and friends come to compete for a little more than bragging rights.
Quick, someone teach me how to fish so I can win this tournament!!!