Skat Trak 12/20 Prop. OK for my setup?

[edomund]

I have a SN with a 650 6M6 cylinder bored over to 80mm (701) with moderate porting and a 61X head. I got a skat trak 12/20 prop off a local guy.

Is this prop too big for flatwater freestyle? Will it not have any bottom end? I see a lot of guys running the hooker 9/15.

Thanks,
Ed

 

[edomund]

 

[Matt_E]

Comparing it to a 9/15 pitched hooker is meaningless. The pitch is useful only when comparing the same model impeller. This is because of different hub diameters, blade areas, etc....
That said, I've never seen a /20 pitched impeller ran in a stock 144 SJ pump, much less a 650.

 

[edomund]

Yeah thats what I was afraid of. I bought it off a guy when I was buying something else from him. I should have done more homework before buying it.
Matt E thanks for the input.

 

[Matt_E]

You might try it and see what happens. It sounds too steep though.

Btw, at 80mm bore, that cylinder sits at 683.6cc.
701 stock bore is 81mm

 

[Shonuff]

Yep, sounds too steep to me too. 12 is an angry pitch to sludge through the water with a 700cc motor and that's a big (8 degree) spread.

Should have fast top end though.

 

[edomund]

Thanks. Matt E, I meant 81 it has stock bore 701 wisesco pistons.
So what impeller would you guys recommend for a 701?

 

[Matt_E]

Depends on your budget.
I used to run an old school Skat 9/17 in my 650 and later a 701. It worked great and was very low cost. Same impeller as what you have pictured, but lower pitch.
If you got more money, look into a Skat Swirl / Skat Freeride swirl in 12/15.
Or get a stock 2008, 2009, 2010, 2011 Superjet impeller. Almost the same as a Hooker, but cheaper.
If you want to go all out, order a low-pitched hooker.
But you'll end up with an impeller worth as much as your motor.

 

[swapmeet]

Not to thread jack, but I've got a ported 701, FP, head, etc. Picked up a Scat Swirl 12/17.

From what was suggested about the 12/15, the 12/17 will provide pretty good low end?

 

[BruceSki]

a 12/17 skat swirl provides plenty of low end. I used to run one in my sj. Had it repitched to 13/18 now to try with my 865.

 

[Tyler Zane]

i roll a 12.5/17 and love it. but hell i dont know any difference, i just know there is no slack threw out the entire rpm range. all in all Matt said it all in post #8