I have a Super Tigre 4.4 at 2.5hp 30,000 RPM and I also have a Nitro Star 4.6 at 2.9 hp 32,000 RPM I was going to use one of those and also fabricate a clutch system so the motor could build some RPMs before it takes off. The reason I am trying to use one of these motors is because I am building this boat on a budget and I happen to have found these motors for free the Nitro Star is brand new never used broke in or anything. I was looking at marine engines like the 61 that was in it and they only make like 2-3 hp that I have looked at and make a lot less RPM's so I didnt think that using one with more RPMs and the same power would really hurt anything. The original motor that was in it was junk when I got the boat it was an Irvine 61 which made like 1.3 hp and 22,000 RPM's by the specs that I found so I thought one of these motors would be a big improvement........................ If I can make them work anyhow