Kawasaki 300 – Sleeper Engine and Pump Mods

Sleeper Engine Modification Kit – The 300 Sleeper engine kit, by Group K, is a quiet and reliable engine modification package that offers a totally stock looking engine compartment together with acceleration and peak speeds that will let you easily run with any stock 550. The wide powerband gives snappy acceleration at all waterspeeds, and the top speed increase is enough to let you go riding with the “big boys” and not get left behind. Our careful upgrading of the top end, cooling system, and intake system will make your 300 operate consistently and reliably on 92 octane pump gas. The detailed installation, maintenance, and tuning instructions will assure that you’ll have all the information you need to make your 300 everything that it can be. The Sleeper kit can also be suited to accommodate any aftermarket bolt-on parts that you may already have.

Peak water speed (with pump kit) smooth water; (js hull)-37.1 mph (sx) • hull-35.6mph

Sleeper pump blueprinting- For the 300 owner who wants a pump that’s up to par with a high output engine, Group K offers blueprinting and finishing of the pump vain case along with scoop grate matching. The end result is a ready to install pump assy that can process significantly more water per impeller revolution, and cavitates less in rough water. The result is better peak waterspeeds and acceleration in rough water conditions. (note: pump nozzle boring is not included since it’s part of our engine modif. kit)

Options:

Sleeper cylinder & head mod. only – The heart of the Sleeper kit is available separately, for the owner who has other bolt-on modifications already in place.

Ignition flywheel lightening – your flywheel loses .8 lb. To permit much quicker throttle response and better overall acceleration. Your engine will still retain full charging capabilities and smooth idling characteristics.

Cylinder boring – The top and bottom of your cylinder are prepped to assure flat locating surfaces. Then we bore, hone to size, and chamfer the ports of the cylinder. (piston is required for proper clearance setup, supplied by customer or Group K)

“Air Leak” Pressure test kit – The lower end of your engine should be totally air tight up to 8 psi. New engines pass this test with no problems. However engines with deteriorated crank seals or brittle intake gaskets can allow outside air to leak into the lower end during operation. This “air leak” can make the fuel mixture lean enough, at high rpms, to cause a piston seizure. Air leaks, not engine modifications, are by far the number one cause of watercraft engine piston seizures. Group K offers a simple to use pressure test kit that allows you to quickly test for any air leaks that your engine may have. This kit comes with block offs that will allow you to pressure test any Kawasaki, Yamaha, or Sea Doo model watercraft engine.