Does anyone know what difference changing from 1.5 to 1.35 ratio gears makes in XR drive in terms of prop pitch and size. I'm wanting to lower rpms a little without going to bigger props.

I did this as ,i did a gear box one xmas eve and couldnt get the same gear ratio,think i dropped about 500-600rpm ,i had a bravo one .At a guess it would equal around 1 1/2 to 2 inchs in prop pitch.It was pushing a 20ft wakeboard boat .I was proped for skiing i could hit nearly 6000rpm which was too much back to about 5500rpm.

I'm not sure if this is the answer you are looking for. My stock setup was 1.50:1 Gears on 26" labbed Bravo's @ 5200 with 385 Hp motors. My current setup is 1.34:1 gears with labbed 28's & 650+ hp same RPMs.
I would think you would need to drop at least 2 sizes example: 30 now 26 with the change.

Probably looking at a 600-800 drop in rpms with just the gear change. It will depend some on your torque curve.

I used prop slip calculator and estimated 550 rpm loss without prop change. Thanks guys.

That's about what it will be.

I've been trying to figure out why I can't get my motor to spin the required 6100. I'm always about 500 short of that. The other night (after talking to a buddy) we started thinking about the gear ratio issue, sure as $hit, 1.34's in lieu of the 1.5's that were supposed to be in lower.

heard a story like that cept it was twins ....They searched for weeks for a problem with the Motors, tach's ect .... Finally found one 1.50 and one 1.34 .....m

Thnks. If I switch anyone interested in 31" P5Xs with about five days of use on them.

Few details on the props? Diameter, Stock, labbed, How much? Send me a PM if you would. Thanks