- Location
- Grants pass
What is the best pitch impeller to run on a 650 sx with mild aftermarket stuff on the motor? Plus does anyone recommend boring the reduction nozzle and how many millimeters are recommended
650 sx pump tuning
- Thread starter Panzica59
- Start date
Those old Kaw pumps liked straight pitched props the best. Look for a skat 15 or 15.5
The nozzles are plastic if memory serves me correctly? Don't try boring them, they will break. Look for an ocean pro alum nozzle and turn nozzle combo. I'll have to dig thru old notes to see what we used to bore them to? I bet it's close to 25 years since I played with them!
Robert Sands in Vegas still has a pile of vintage Kaw parts. He might be your best bet in finding what your looking for? He is not on the X. His old site was jetskimechanic.com. Other than that, fleabay will be your friend. Good Luck!
The nozzles are plastic if memory serves me correctly? Don't try boring them, they will break. Look for an ocean pro alum nozzle and turn nozzle combo. I'll have to dig thru old notes to see what we used to bore them to? I bet it's close to 25 years since I played with them!
Robert Sands in Vegas still has a pile of vintage Kaw parts. He might be your best bet in finding what your looking for? He is not on the X. His old site was jetskimechanic.com. Other than that, fleabay will be your friend. Good Luck!
The stock 650 nozzle is big enough, the only way to go larger is with a now hard to find aftermarket nozzle. A straight 15 will pull harder than 15.5 or 16, these maintain speed better in races. A modified low pitched big hub 750-800 impeller is best. A 750ss/xi shaft can be used for customizing spline engagement.
Last edited:
- Location
- Mammoth Lakes CA
The X2 nozzle is bigger and will bolt on
Vumad
Super Hero, with a cape!
- Location
- St. Pete, FL
Nozzles are cheap enough that if you want to try boring them you can just buy an extra and give it a shot. My buddy used a drill press and a sanding drum to take off about 1mm. It's not precise work, but it helped him get it to spool up a bit faster w/o having to try different props (I had a few extra nozzles). I had a stubby tail cone and he liked the results from the nozzle better.
If you do go to a x2 nozzle, you can use a sxr steering cable or make an extension using the long nut and a threaded rod from the X2 trim system to lengthen if the steering if necessary.
If my memory serves me correctly, the 650sx is 81mm, the x2 is 83 mm and the PJS aluminum is 87mm, SXR was pretty small something like 79mm. The PJS was way big for me w/o a prop change so I sold it. I think it went for almost $300.
If you do go to a x2 nozzle, you can use a sxr steering cable or make an extension using the long nut and a threaded rod from the X2 trim system to lengthen if the steering if necessary.
If my memory serves me correctly, the 650sx is 81mm, the x2 is 83 mm and the PJS aluminum is 87mm, SXR was pretty small something like 79mm. The PJS was way big for me w/o a prop change so I sold it. I think it went for almost $300.
- Location
- Grants pass
Thanks guys, it's has a stubby cone already, the reduction nozzle is cast, I'll try taking 2 mm out of it, so you guys are saying 15 degrees on the leading edge and trailing edge?
- Location
- Two Rivers WI
Best impeller is a Skat 8/16. On my 650 I started with a 9/17 and it was slugish. I had a pipe, 44, head, on a fresh built motor. The 8/16 was by far the best and everyone was surprised how well that ski rode. I would start there, and tinker if needed. Anyone who says that a straight pitch is better than a variable pitch in these pumps is a moron.