You may be able to pull the prop off and look inside the hub. I would think a 225 Opti/ Jaguar will probably need a 25 Pitch. Whatever you decide, you would be FAR better off getting a Merc prop, either the Tempest 3blade or Trophy 4blade. They both have a PVS plug system, that allows the vent holes to be plugged in various sizes, thus helping with performance (holeshot). If you have a friend or local shop that could let you try one out would be best. The Jag was the heaviest 20 footer, and with both tanks full(52 gal of gas), you will not get a great holeshot especially with a 225, so you may would opt for the 4 blade for better load carrying/ bow lift. If at all possible, can you get buy with less fuel? Hope this helps.Last edited by jignpig on November 25th, 2007, 8:05 pm, edited 1 time in total.96 Eyra/12 Mercury 175 Pro XS with 2015 single axle trailer2017 Victory Gunner