SS prop performance changes

[flybuddy]

Have an 07 Hurricane 196RE with a FS115 Yamaha. With the stock prop it ran 40mph with a max of 5800 rpm. At approx 20 hrs I got a minor ding in that prop and elected to go with a SS Stiletto. Same pitch and diameter (13.25X17). Unfortunately performance dropped to 38 mph at a max (WOT) rpm of 5225. I assume the cupped prop aspect had something to do with it. I got the stock prop repaired and remounted it. Now rpm is 6025 and 38 mph. It appears they ground a bit off all 3 tips to balance it. I called Stiletto, they were helpful and offered to exchange for a 15" pitch. I just put that on and have yet to test. I'll post results when I do but I believe I'll be up around 5650 with it and hopefully be back at 40 mph.

 

[Tail_Gunner]

Re: SS prop performance changes

If that motor is a 4 stroke it's setup for 5500-6000 rpm, If you watch some of the guy's post here you will find that they almost alway's prop a motor to it's max rpm in this case that might be 6000.

If it were you id see if you could get Dhadley
to chime in here. I havnt seen Walleyhed post for a while ( hope thing's are good) , but if im reading this right you got 38mph @ 5228 with a 17p Stilleto, and indeed if that is a 4 stroke im sure 6000 is the target for max efficency. Making that 15 good for 5400-5500 abit over.

Now if it's a two stroke it's dead on but i dont think so... You may also letm know your running a deck boat with a 11 degree draft, it would be intresting to see if a 4 blade would provide enough lift aka less wetted surface yeilding a better hole shot and increased midrange and a very litte cost in speed?

 

[Silvertip]

Re: SS prop performance changes

Engine height was not mentioned here. Always good to check that before spending money on props.

 

[Tail_Gunner]

Re: SS prop performance changes

It's a deck boat, ok settle down tail boy, i can almost assure you no one has talked to him about prop height........it's a deck boat. Orignally over propped ???? could that really effect it that much?

 

[flybuddy]

Re: SS prop performance changes

It's a 4 stroke, manual says WOT rom should be between 5000 to 6000. Don't know engine height, how can I determine? It does seem to ride better and faster with about 3/4 up trim. I'm taking it out tomorrow with the 15 pitch Stiletto, I'll see what happens and post the numbers.

 

[flybuddy]

Re: SS prop performance changes

Ran it today with 15 pitch Stiletto, it's right back where I started. 5800 rpm and 40 mph. Although top end the same, the hole shot is much quicker. Happy overall.

 

[Tail_Gunner]

Re: SS prop performance changes

There are some tweaks you can do from here, One is raise the motor, i do not know what type of transom you have but you should have a series of mounting holes. If you can raise the motor one notch at a time until cavitation comes into play. you should get better econ and speed

There are plenty of OB guy's here who could help you here far better than i. Good luck....... There are times i wish i had picked up that type of boat it look's like great fun....8)

 

[flybuddy]

Re: SS prop performance changes

Thx, I'll take a shot. It's been a sweet boat for what we do with it, wouldn't be optimal in rougher water with the tri-hull.