I have a 04 30' Spectre with twin 2.5's and 1:86 gears. When I bought the boat it came with 15 x 32's and it spun 7500 rpm's @ 107 mph in salt water. Now I have the boat in fresh water and I can only spin 7000 rpm's at 100 mph. I put a set of 15 x 28's on and the boat hit the rev limiters running 94 mph. Obviously I need to find a set of 30's but my question is can I turn my 32's into 30's or do I need to get a new set of props? Looking at the 32's it looks like the previous owner had them worked on already. They are thinned out and it looks like the leading edge of the prop has been shaved about 3/16". Any input would be greatly appreciated.

You can downpitch the propeller 1 inch to a 31P which is good for approx 200 RPM. The next question is whether your prop is Lab Finished or not. If it is stock, with thin edges then you may possibly be able to lab it for an additional 250 RPM. If it is already lab finished then we could possibly look into a diameter reduction, for the additional RPM. Hope this helps.

Julie

Removing diameter to increase rpm in a no-no unless it is the only option or the boat's running attitude needs to be adjusted.

Agreed, Lab Finishing the propellers will give you 300 additional rpm if they haven't been done. We also have special templates that can offer even more performance on these propellers. It sounds as though your props have already been worked on and may limit our ability to adjust them.

One more thing, The 32's and 34's are different from the rest of the Merc cleaver line.

Give us a call if you would like to discuss this further.