another prop question!

Tbradley

        Hey Guys, I have a question about changing my aluminum prop to SS.  Heres my info: '06' GS202 sporting a DF140 with current prop Solas 13.75x17, with 1/2 tank of fuel and the family its turns 6000 wot at 36 mph (gps), which I'm ok with.  Holeshot is ok, would like it to be a little better if possible.  My prop is dinged up pretty bad and I want to change to SS.  I'm having trouble locating exact same size, so my question is this.  If I go with a 14" SS prop with 17 pitch, will I see any difference adding 1/4" to the diameter and and changing material?  Or if you guys have another suggestion, I'm open.  I mainly tube the kids and ski a little, and cruise.

Thanks

Tim

nquirk

Prop diameter is a function of prop design. If you compare different pitches in props of the same model from the same manufacturer you will see that as pitch goes up, diameter comes down a bit and vice versa.

You cannot simply compare a 13-3/4 x17 aluminum to a 14x17 SS. They are simply different designs. Generally however, diameter will not affect RPM or performance nearly as much as pitch. When you change from aluminum to stainless, change the number of blades, change prop manufacturers, and prop models, you introduce so many variables it's hard to tell what you will end up with.

So, as a starting point, first measure the clearance of the 13 3/4 prop and the anti-ventilation plate above.  Is there clearance or do you have the largest diameter prop available to fit that motor.

Second, what is the top of your RPM range for this motor (you're turning 6000RPMs) but what is the top of the range.  You want to get as close to that as possible.  Going to 14" diameter, and maintaining the same pitch you may be fine, but you first need to know the top end RPMs suggested for that engine and based on the variables you already know, you can start to determine if simply adding another 1/4" diameter should be fine.  I would think it may be possible but the RPM range will be key to this.

Tbradley

Thanks,

Max rpms is 6200 and Suzuki says 14" will work.  Right now I have about 7/16" clearance from from the top of the blade, so I think I'll be fine.  I guess what I'm looking for is a ss prop that is close as I can get to what I have, because I happy with the overall performance.  I just don't want any drastic changes.

Tim

nquirk

If that's the case, I think the 14x17 SS will work just fine and you won't over rev the engine and be in a proper RPM range.

I don't think you'll see anything change getting on plane, etc as you'll be maintaining pitch but possible increase/decrease in speed of +/- 1MPH.