It's all about running at the top of the rated rpms at Wide Open Throttle, trimmed for best performance, normal load. Data I have says 5600 is that spot and you prop for that or reasonably close. 2 stroke engines are low cubic inches (low torque) for the HP and need rpms to get their HP: HP = (torque x rpm)/5252 . HP is what twists the shaft so that the prop can develop the required thrust.
You have plenty of HP for that boat. BTDT You have enough to pull 2 slaloms with several folks in the boat with ease. Tubes or boards or whatever else not a problem. It should also get you up in the 50-55 mph range with the same prop.
Thing that causes the biggest problem in a boat such is that cross seat in front of the engine. Getting on plane (up on the water) requires getting the stern up. Your first disadvantage is the high dead rise at the transom (thing the engine is clamped on). Great for smooth riding in rough water but does take more whoopie to get up. Second a hull like yours doesn't flatten out like a semi V with a flat transom once on plane. It will remain somewhat in the water but you have to have that to get the smooth ride this baby will give you and I guarantee you when you are pulling a couple of slaloms at 35 or so, a smooth riding boat, in busy or rough waters, is a real plus. BTDT too.
After that you have 400# of engine back there then a 50# battery and anything else you tuck behind the seat. 100# for the seat and 300 more for a couple of adults on the seat......factor it in because folks LOVE to sit back there. So you have a lot of weight trying to keep the stern in the water. Any bow riders will help to offset that but you need to offset it one way or the other to get up, especially if you have a couple of slaloms pulling against you, all of you needing to get on the water simultaneously.
3 things that can help that are: Ported prop, 4 blade prop, or trim tabs. The 4th is your trim position and you have to play with that to find the sweet spot. Usually tucked all the way in against the transom gets the bow (front) down faster but depending on all the variables, especially with adequate HP which you have, it may not be necessary.
So my suggestion is this. Next year get the boat out and get used to it. Run it through the paces and loads and activities. After you get some time with it/on it then come back with your findings and someone on here will help you tweak your performance. Otherwise doing anything now would/could just be a waste of money. You may have what you need on there right now.
Mark
