Boyesen for 15 HP Evinrude

[steffen300]

I have a Evinrude 15 HP Outboard from 1996 on a Bombard 12 ft Inflatable Boat , I want to make a tune-up with boyesen reeds.Who can help me finding the correct carburator jetting?If anyone has some experience to get a little bit more Power in my Evinrude please help me.I heard from People drilling bigger holes in the inner exhaust.For what I have to look before mounting the Boyesen?I have experience with 2-Stroke Motorcycle engines, but not with Outboards ,so I hope that anybody of you guys can give some tips to a German gearhaed.I?m also searching for a online-store where I can order some spares for my Evinrude.
Best whishes from Germany
Steffen