Chris:

In the PRO category where I did all my competitive racing, some of us had a saying that if you were knowledgeable about the "Two P's" you had it 90% of the way to winning. Two P's meaning Pipes (Expansion Chambers) and Props. Your motor I believe, has a "tuner" in the down housing which is similar to the pipes we used to experiment with. Fast Fred has done a lot of work in this area and probably could be of help. Props are another BIG thing to experiment with and test with, as much can be achieved with the right prop and set up. Ron Hill, who of course is the owner of this site, has many years of experience with props and could possibly be of great help to you.

I also just noticed that you are from Covington, the home of Hopkins Propellers. I purchased many very good propellers from Floyd Hopkins who started the business, and who his son, Glen, I believe still operates. Several of the props Floyd furnished me were used to set competition records in the class's I ran in APBA sanctioned racing. If you do not know Glen, perhaps you might want to get acquainted with him as he could probably be of great help, especially if he could find the time (or be paid to) go testing with you and make some changes right on the lake or river bank. You need several things to test props successfully, one of which is a speedometer or GPS, and the other a tachometer so you can see the RPM differences in the props as you both test them and then change the set up (height and kick out or in). You can't really do a good job with out both these instruments to achieve what you are trying for. I suggest Glen because he is right there locally (if still in business) and being his fathers son, I am sure he is knowledgeable about props if he learned 1/10th of what Floyd would have taught him.