Oil change and 60 hour service

[BertInTexas]

I had my ski serviced two weeks ago,oil was changed and whatever else they do,and have been out twice since.Both times I only maxed out at around 7600 rpms,and gps at aroung 62-63 now,The past two summers I have ran 7900-8100 most all the time,and gps'd 67-68 consistently.I checked the dipstick after warm up (in the water) and it is about at the top of the top bend.So,I need to remove some oil,right? How much? And where do I get the "thingy" to do it with? Thanks in advance guys

[BertInTexas]

Ok,seems there is a similar post I missed.I am losing (missing) a good 400-500 rpms though............?