I currently have a 2000 merc 90 fourstroke on my 01 700 LX. I have it set up great with doing 50 mph on gps. Just got an opportunity to buy a 2003 merc 125 2 stroke. Oh boy! Can I expect big gains? Or is it ganna be a job not worth getting into? My goal is to get 60 mph on gps with the upgrade. Any thoughts?