Best performing Prop for 1801

[Underwoodbb]

I have a Parker 1801 (02) with a Yamaha F115TLR two stroke (02). Believe it has a 2.15 gear ratio. I have the stock propeller that came on it (believe it may be a black aluminum 13x19 or a black stock SS), but not sure.
Anyway, I am open to improving overall efficiency and performance and I am told changing the prop to a performance Stainless Steel will help a lot.
I live at Carolina Beach and would appreciate your advice regarding what to buy. Overall I have average pick up, cruising at 4,000 / 25 mph with a top speed of 40mph at about 5,600 RPM. Most of the boats around me have SS props, some four blade, others three.
What are your thoughts and recommendations?
Thanks,
Bob

 

[BradH]

First off...is it a F115 (four stroke) or regular 115 two stroke? Think most all 2S engines came with 2.0:1.

Not exact setup but might help...I have a 1992 1700 with an '06 115TLR 2S. It has a PowerTech SCD 3 blade 19" pitch SS prop. I have been told it's basically a SS copy of the prop you have...painted aluminum semi-cleaver designed for stern lift.

I would not recommend it as I doubt you will see much performance gain. So scratch that one off the list of 20 or so available props. It's horrible on my boat but apparently works well on some others.

My recommendation would be getting a hold of a good prop shop (I like Brett at www.bblades.com) and your local dealer and try a bunch of them. Most are really good about this.

Start playing with prop slip and run all the props you can beg, borrow or steal.
http://www.go-fast.com/Prop_Slip_Calculator.htm

15% at WOT is not bad at all, 12% might be possible. 25 mph at 4000 concerns me with 24%, even worse at 31% if it is 2:1.

If you're really concerned about efficiency, I'd get some type of fuel flow meter and dial props/speeds in on that. Otherwise try a bunch of props, take notes on feel, and try to minimize the slip at cruise and WOT, but still have it reach 5500.

The Yamaha performance bulletins for these engines are still available, take a look at rpm and gph, most are fairly consistent for every engine, independent of speed.