Top End Rebuild Kit 250/260      $736.80

Top End Rebuild Kit 300/310      $736.80

Top End Rebuild Kit 15F/LX/160/SXR      $660.00

Top End Rebuild Kit 12F      $653.90

Fuel Pump and IN Tank Regulator for 15F/ LX

Kawasaki Big Bore Kits

(Add extra Horsepower to your race machine! Extra fuel needed. Please contact us for details! Comes with pistons, oversize racing head gasket and Big Bore Cylinders. Cylinder core required. N/A Kits have an option to add the appropriate parts to upgrade the fuel system. All kits REQUIRE 93 Octane Fuel unless you request another compression ratio!)

Cast Pistons/ Oversize Forged/ Replacement

(All pistons do not come with rings, pins or snap rings unless specified. Piston kits come with rings, pin and clips. A piston kit is a set of one. Pins, and snap rings are all individual unless in a kit, which covers 1 piston. All 250 pistons below are upgraded to 260 pistons which are a direct replacement, but higher compression. 310 OEM pistons below are prone to breaking, KP HIGHLY recommends using forged, but if you cannot, use 300 pistons or 300/310 Aftermarket.) 

OEM Ring Set 250/260           $51.49

OEM Ring Set 300/310          $56.71

Aftermarket STD Ring Set 250/260     $33.32

Aftermarket STD Ring Set 300/310    $33.32

OEM Pin                                $23.60

Aftermarket Pin                      $5.94

OEM Snap Ring ea.                    $2.95

Aftermarket Snap Ring Set     $3.66

+300 RPM

NEW Ultra 250/260 Cylinders              $1,214.74

Re-plated 250/260                       $789.95

NEW Ultra 300 Cylinders                     $1,194.29

Re-plated 300                              $789.95

NEW Ultra 310 Cylinders                      $1,286.16

Re-plated 310                        $789.95

NEW 15F/SXR 1500/ STX 160 Cylinders     $1,146.76

Re-plated 15F/SXR 1500/ STX 160       $789.95

Ultra 250/260 OEM Piston                                  $61.87

Ultra 250/260 .01mm Oversize Kit                    $150.53

Ultra 250/260 .02mm Oversize Kit                    $150.53

Ultra 250/260 Aftermarket Piston Kit               $100.12

Ultra 300 OEM Piston                                  $72.20

​Ultra 300/310 Aftermarket Piston Kit        $150.53

Ultra 300/310 .01mm Oversize Kit             $150.53

Ultra 300/310 .02mm Oversize Kit             $150.53

Ultra 310 OEM Piston                                  $72.20

Comes with a set of 4 pistons, and complete upper end gasket set. As pictured above.

Ultra 250/260 9.5:1      $989.99

Ultra 250/260 7.8:1      $989.99

(For 90 Octane, Alaska, Canada etc.)

Ultra 250/260 10.5:1    $989.99

Ultra 300/310 9.5:1      $989.99

Ultra 300/310 7.8:1      $989.99
(For 90 Octane, Alaska, Canada etc.)

Ultra 300/310 10.5:1    $989.99

15F/SXR/Ultra LX 12.5:1     $1,149.99

High Output Lightweight

Forged Pistons (With Tuff Skirt Coat)

15F/SXR/Ultra LX 13.5:1     $1,149.99
High Output Lightweight
Forged Pistons (With Tuff Skirt Coat)

Kawasaki Ultra 250x 260x 300x 310x JE Forged Pistons 83mm (MADE IN USA)

(Kawasaki OEM pistons are well known for breaking under load, due to their thin cast design. If you are an everyday rider and want the reliability out of your ski, we recommend upgrading! These pistons will withstand anything you throw at them! Forged and machined from the highest grade aluminum these pistons are specifically designed for high performance and extreme conditions. Drilled oil holes around the pistons provide added lubrication and cooling. KP does not use the JE ringset (JE rings are very hard to seat), we have our own rings that we have specifically developed for use with Kawasaki watercraft. Our rings are very strong, lightweight and a very thin race profile for optimal performance and reliability. No more GIO issues, no seating issues, plus far superior ring sealing! Can be used with stock connecting rods. We recommend the 9.5:1 as a direct replacement for stock pistons. The 10.5:1 pistons will provide even more power, but we do recommend race fuel for the 300/310's. 93 Octane gasoline can be used with 10.5:1 250/260 pistons, this is temperature dependent. 15F/SXR/Ultra LX pistons come standard in 12.5:1 for direct stock replacement on 93 octane gasoline. For other compression ratios, please contact us! We can make them! Comes with a set of 4 pistons, clips, rings, and pins.)


Replacement Ring Set                                              $27.94/set

(One set is for one piston, fits all models,

STD size. For 86mm please contact us!)              

Replacement Snap Ring Set                                     $2.63/set

(One set is for one piston, fits all models)     

Kawasaki Ultra 250/260 86.00 mm     $2799.95

Kawasaki Ultra 300/310 86.00 mm     $2799.95

15F/SXR/STX 160/Ultra LX Lightweight Forged 86.00 mm 12.5:1 Compression     $2799.95

(We also have 13.5:1 and 14.5:1 compression)


Fuel Pump and IN Tank Regulator for SXR and STX 160

15F/SXR/Ultra LX

83.50 mm Oversize  $864.95

84.00 mm Oversize  $864.95 

​(12.5:1 Compression Standard)


(Cylinders are new OEM. If replacing 300 cylinders, we recommend upgrading with NEW 310 cylinders for better cooling. We can only supply a core-on-core exchange. We cannot exchange 300 cylinders for 310. A good core required prior to purchase re-plated, if not there is a $375.00 core fee. Any cylinders that need over sizing will not be accepted. Any damages may be subject to a welding fee. Contact us for availability.

Kawasaki Ultra 250/260

83.50 mm Oversize  $864.95

84.00 mm Oversize  $864.95 

Kawasaki Ultra 300/310

83.50 mm Oversize  $864.95

84.00 mm Oversize  $864.95


Premium KP Forged Oversize Pistons

(Pistons come as a set of four, they come with forged pistons, premium racing rings, high strength snap rings, and high strength pins. Your cylinder bore will need oversizing, you can ship your cylinders in for us to re-plate and oversize. Bigger bores will require more fuel, either by increasing fuel pressure or a fuel tuner. Standard compression is 9.5:1, but these can be made in other compression ratios of your choice at no extra charge. Please contact us if you have questions! 1-3 week lead time.)

Cylinders/ Pistons

KP recommends exclusively using forged pistons on all Ultra's. Rings, pins, clips and pistons are bulletproof when it comes to ultra reliability. Worry no longer! Upgrade to forged today!

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