Engine RPMs at WOT on 2007 197TT
 

My 2007 197TT has the MCX w/Powerslot tranny, and a OJ 13.5 x 15 prop with a .80 cup. When I run at WOT, the engine is turning approximately 4500-4600 RPM.

In reading the manual, the specs for the 197 indicate Max allowable rpm at WOT of 4800 to 5200. But the spec also calls for a 12.5 x 12 prop when the same engine/trans are mated.

On the other hand, I have heard that one of the "mods" for the TT Edition is the 13.7 x 15 prop. My question is two-fold:

1. Can anyone verify that the TT should be using the prop I currently have mounted?
2. If so, would this difference from "stock" account for the fact that my WOT RPM is less than called for in the manual.

Boat runs terrific in all respects and I have all the speed I need--just trying to make sure I'm operating it within the correct tolerance and not risking any issues. Many thanks in advance!

The 12.5 x 12 prop is for the 1:1 trans. The factory powerslot prop is 13.7 x 17. The fact that you have less pitch and less WOT rpm confuses me. I would think that you would be banging your head on the rev limiter with that prop.

Check the ratio on your transmission tag. A 13.7 x 15 .80 is used with the 1.26:1 transmission. I know absolutely nothing about the TT boats.

The gear ratio is 1.26:1 in TT boat. The 13.7 X 15 is the correct size for that ratio.

Thanks Eric! So is it fair to say that the 4600RPM wide open os about what it should be? Thanks again.