zpilot

I now have all my parts to build my Kawi Sport Cruiser but need to understand the reduction nozzle to continue.

NOW


PJS Viper 9000 800cc 90HP
Jetinetics LW Charging Flywheel
650 PJS Exhaust Manifold
650 SC Coffmans Exhaust full system
Skat Track 12 vein Magnum pump 140mm
Skat Track 10/18 SS Impeller


With the added power, and I'm assuming alot more pressure in the pump do to it being 12 vein vs stock, do I need to increase my reduction nozzle size to get the water out faster? The stock reduction nozzle is 82mm on the SC.

My goal is top end performance with decent low end.

upstand2

82mm should be ideal for lowend.

bkoche

thats going to be a monster of a sleeper ski

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2004 SXR - FPP Wetpipe, Blowsion railcaps, 4deg bars, billet clamps
1994 750sx - Loaded -FOR SALE
1983 JS550 - WC RC520 reed cylinder, WC Head, PJS WB, Dual 38SBNs, WC 750 reed stuffers, WC Stacks, WC 6.5gal tank, FPP Halfpipe, SBT High torque starter, 16.5 Skat, Blueprinted 440 pump, lightened driveshaft, 76mm OP nozzle, Jetsport bulkhead brace, 90wt mod, WC scoop, Rend plate, Rear exhaust, Carbon Fiber

1991 Honda CB750
1976 Suzuki RE5A
1976 Suzuki GT750A
1975 Suzuki GT550M

zpilot

82mm was stock on the ski so Im wondering if I should size up or down after the changes. Is it as simple as monitoring the RPM's to see what is correct?

It makes sense that Kawasaki put the 82mm to get it out of the hole better vs a 650SX or other 650's, but since my pump has more veins now don't know if the rule changes or which direction to go.

The ski was not made to go fast, but now it is.

kawi105

mag pump in an SC?

original..

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zpilot

Its the orignal pump sent out to Skat Track converted to a 12 vein magnum pump. I ride a stand up as well, but SC's are too much fun. It just a great feeling going 50+mph in a SC.

My old SC with the Viper.

Attached Images

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Wet Wolf

hehe, you don't need to understand an exit nozzle yet. you need to get that thing on the water, make sure it floats, then work on dialing everything else in before you worry about the exit nozzle. You shouldn't even be messing with a 12 vein pump unless you have an 1100 in there.

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Bruce Wolford (509) 280-5444 - Pump Performance
http://www.wetwolf.com

Any electricians out there? Check out this new tool... http://www.d-reamer.com

zpilot

Wet Wolf,

Thank you for your input. I don't question your knowledge, but Skat Trak's site has a chart that says "The 12 Vein Configuration is recommended to accelerate and hook up best for all 785cc -1100cc".

I know the ski floats, I've ridden the ski with this motor in it. The pump is the original but modified internally to a magnum, so no hull mod's were needed.

Are you saying that the magnum will be a disadvantage to the ski?

upstand2

That engine will be a nice upgrade but it's going to be the same as a piped 750.Good but nothing earth shattering , the mag pump is definatly nice but not really needed. Not bashing you, I have a Viper 700cc myself.

zpilot

Thanks Upstand. Would a piped 750 keep up with a 800SXR? The viper 9000 has 10HP advantge to the Kawasaki 800cc so I think it could be closer to a piped 800. I know it's not super powerful but with a stock impeller, pump and half arse carb tuning, I was hitting 46-47mph.

I went to see Aaren Davis who did the R&D on the motor and he said it's closer to 100-110hp as they marked the power lower on paper. I bet a SXR motor in the SC would do low to mid 40's since it does hight 40's in the original hull.

Pretty sure your Viper 7000 was capable of 50mph in the VHP and that's 20hp less than the 9000.