Tear the carbs apart completely,clean every opening with spray cleaner,blow air through every opening.
Buy carb rebuild kits from iboats.com.,put them back together with the cab rebuild diagram in front of you, focus this is harder than it looks
Free factory service manuals at www boatinfo.no/lib/library.html, click yam find your motor,find your cab not cab carb,it's almost 5 here.
It has a choke system, it will be in service manual.
