ULTRA 260/250 PERFORMANCE KITS RIVA ULTRA 250 STAGE 1 KIT RIVA Ultra 250X Performance Power Filter Kit RIVA Ultra 250X Valve Cover Block-off Kit RIVA U ltra 250X Free Flow Exhaust Kit RIVA Ultra 250X Top-Loader Intake Grate RIVA Ultra 250X Performance Ride Plate RIVA Ultra 250X Pro-Series Sponson Kit CLICK FOR LARGER VIEW PARTS & ACCESSORIES HYDRO-TURF MATS HT62 $89.95 HYDRO-TURF SEAT COVER SEW62 $160.00 K&N PERFORMANCE GOLD OIL FILTER KN204 $12.95 K&N powersports oil filters are ‘TUV’ product endorsed and ‘TUV’ factory production monitored. This means every K&N oil filter is equal to or will exceed all OEM specifications. Our filters contain a modern synthetic filter media, designed for ultimate flow with less pressure drop, yet engineered for outstanding filtration to meet or exceed all OEM specifications. All K&N powersports ‘spin-on’ oil filters feature a heavy-duty metal can with a 17mm nut affixed onto the end that allows for easy installation and removal. The 17mm nut is crossed-drilled so racers can safety wire the filter to their pwc. KAWASAKI PUMP WEDGE $30.95 INSTANTLY ADD 1+ MPH NGK LASER PLATINUM SPARK PLUG PMR9B $16.95 R&D AQUAVEIN SCOOP GRATE 111-25000 $194.95 The new R&D Kawasaki Ultra 250 Aquavein Intake Grate Kit has been designed and developed with all new performance concepts in mind to deliver the ultimate handling and speed performance in recreational, offshore, and closed course race conditions. The new R&D Ultra 250 Aquavein has been extensively offshore, race track, and 1 and 2 up recreational tested to guarantee reduced cavitation and maximum pump hook up in any condition. The R&D Ultra 250 Aquavein will deliver quicker acceleration, higher top speed performance and a much smoother and more predictable ride over the O.E.M. intake grate in rough water conditions. Low speed and high-speed turns are a breeze with new found control. The secret to the R&D Aquavein’s performance is in its patented, award winning, and championship winning wing and twin bar, deep channel design. The well proven R&D top loader Aquavein wing concept has been used exclusively by Factory Kawasaki and Yamaha racing teams to win every Pro 1200 and Open World Championship for a full decade! Bolt on an R&D Aquavein top loader intake grate and experience why R&D is the top selling intake system worldwide. R&D BELT HOLDER KIT 611-25200 $80.40 R&D BOOST GUAGE ADAPTER 611-26002 $34.95 The R&D Boost Gauge Adapter installs between the supercharger and the waste gate and allows the ability to mount a boost gauge to it via 1/8" fitting. This will enable an accurate measurement of boost the supercharger is delivering. Kit comes with gaskets and hardware. R&D CRANKCASE VENTILATION / OIL AND VAPOR SEPARATOR KIT 215-25002 $419.95 The R&D Ultra 250 Crankcase ventilation system was developed to offer a complete bolt on breather expansion kit which will substantially reduce crankcase pressures on Kawasaki Ultra 250’s supercharged engines. High performance engines (especially supercharged) need as much crankcase ventilation as possible. The R&D system doubles the volume of the O.E.M. crankcase breather and triple baffles the oil and vapor pressures within the O.E.M. breather case. The R&D system relieves excess crankcase pressures in the oil breather case and vents high pressures and fuel vapors into a piggyback vapor/oil catch can reservoir. The R&D vapor/oil reservoir mounts and connects directly to the O.E.M. oil separator tank with a quick and easy bolt on installation. The R&D crankcase ventilation and vapor separator system puts an end to oil blow by messes in the engine compartment by relieving excess crankcase pressures and trapping excess fuel vapors, condensation and blow by oil into the R&D oil/vapor separator. Increases engine RPMs and performance by relieving excess crankcase pressures. Decreases oil blow by caused by excessive crankcase pressure in high performance engines. Traps fuel vapors, excess crankcase fuel blow by and condensation in the vapor reservoir and keeps them from entering the intercooler. Helps to maintain a cleaner more efficient intercooler. Helps to reduce and remove excessive fuel vapors and water condensation from the oil system which adds to oil life. A great addition to any high performance long course or endurance competition race machine. R&D COOL AIR INTAKE KIT 215-25000 $116.95 The R&D high performance Air Filter Kit will improve acceleration and top speed performance by increasing air flow and reducing air temperatures that enter directly into the Ultra 250’s air plenum box area. The O.E.M. air plenum box on the Ultra 250 is a great design that will flow plenty of air. However, the air that feeds the plenum box is heated by the engine. R&D has created an easy to install “flat filter” that installs directly in place of the large center access inspection cover located directly under the main glove box. The R&D Flat Air Filter insert will allow unrestricted fresh and cool air to enter the air plenum box area which will add power you can feel and a nice high performance tone. The R&D Performance Filter Kit also features two filters, one for each of the surge and blowoff protection valves. The O.E.M. surge valve recycles compressed hot air back into the air box plenum at idle and under deceleration conditions. The R&D surge and blowoff valve filter kit removes the air recycling hoses which will keep the hot air from entering the air plenum box reducing the engines intake air temperatures. The R&D Ultra 250 Air Filter Kit offers great performance tips on how to remove the restrictive air vent hoses which will further reduce the under seat ambient air temperatures. The R&D Filter system does not remove or alter the O.E.M. plenum box in any way, therefore there are no questions to be answered regarding water ingestion! The R&D Filter Kit is easy to install with no modifications required to the O.E.M. parts. • Improved low end performance • Great high performance tone • Cooler engine air temperatures • Cooler engine compartment temperatures • Easy to install bolt on performance (no modifications) • Low cost performance advantages R&D DEEP FUEL PICKUP 801-25100 $49.95 The R&D Deep Fuel Pickup is designed to maximize fuel volume. The stock fuel pickup is located horizontally in the gas tank three inches above the bottom of the tank. This leaves approximately 5 gallons of unusable fuel in the bottom of the tank. The R&D Deep Fuel Pickup relocates the stock fuel pickup to the bottom of the tank in a vertical position. The new positioning allows for 24 percent more riding time per tank of gas. An absolute must for offshore racing. R&D DRIVER WHEEL HOLDRE TOOL 611-26003 $40.95 The R&D Ultra 250 Supercharger Driver Wheel Holding Tool was developed to secure the driver wheel from moving while removing the drive hubs hardware. The R&D Holding Tool makes it fast and easy to remove and re-install a supercharger wheel without damaging or breaking the wheel hub. Use the holding tool to properly torque the drive bolts and main spline drive bolt. A must have tool. R&D DRIVESHAFT SHIM KIT 161-00810 The R&D driveshaft shims install into the prop snout and remove the unwanted play or float the driveshaft has in the prop/pump assembly. Properly shimming the driveshaft will keep the driveshaft couplers fully engaged. Fully engaged couplers eliminates premature rubber dampner wear and failure. R&D ENGINE PERFORMANCE KIT 611-24350 $1769.95 R&D EXHAUST EMISSION BLOCK OFF KIT 331-25000 $35.95 The R&D Exhaust Emission Blockoff Kit was developed to block off the O.E.M. exhaust emission ports located in the valve cover that connects to the exhaust ports. The Kawasaki labeled “air suction valve” operates effectively under low speed and cruise RPM ranges allowing air to be pulled from the main air box plenum and into the exhaust ports, which will result in a lower measured emission ratio (cleaner). The air suction valves fiber reed pedals can become heat damaged over time which can cause the valves to leak or back flow hot exhaust gases back out of the valve at sustained W.O.T. (wide open throttle) operations. Leaking air suction valves can result in a melted PVC connector T and poor top speed performance. The R&D Air Suction Blockoff Plate Kit will reduce exhaust gas temperatures, lower exhaust back pressures, improve low and top speed performance, and deliver a more accurate and precise air to fuel ratio for precision high performance tuning accuracy. The R&D Air Suction Blockoff Plates are a great addition to any recreational application to remove expensive prematurely worn valves that can cause poor performance. The addition of a R&D Blockoff Kit will be strongly suggested on any stage level of performance modifications on the Ultra 250X. • Inexpensively replaces prematurely worn or leaking valves • Lowers exhaust temperatures • Lowers exhaust back pressures • More responsive low end performance • More consistent top speed averages • More precise AFR tuning R&D FUEL PUMP PRESSURE REGULATOR BLOCKOFF FITTING 811-25100 $21.19 R&D offers a Fuel Pump Pressure Regulator Blockoff Fitting Kit which will allow the O.E.M. stock in tank fuel pressure regulator to be removed completely and replaced with a billet part which is necessary when installing an aftermarket externally adjustable fuel pressure regulator. The O.E.M. in tank fuel pressure regulator is fixed to maintain 40-43 pounds of fuel pressure at all times. For high performance applications where horsepower is boosted, it is necessary to install larger flowing fuel injectors and be able to tune the fuel pressure up or down as needed. Most factory race teams are running 65 plus pounds of fuel pressure along with higher flowing fuel injectors and externally adjustable pressure regulators. The R&D Fuel Pressure Blockoff Fitting is the answer to quickly replace and block off the port. The R&D fitting is manufactured to “Deadhead” or block the port solid, however, the fitting is pre-machined and tapped and can be relief drilled to be able to install a Mikuni Super BN Series jet directly into the end of the fitting for a small in tank restrictor jet which may be helpful for fine tuning fuel pressures in high altitude situations where finer tuning of fuel pressure is necessary. R&D has a complete line up of fuel injectors, fuel pressure regulators, fuel gauge, and fuel hose accessories, all that meet I.J.S.B.A. and APBA approval. R&D HIGH FLOW FUEL INJECTOR KIT 811-25000 $599.95 When boosting the horsepower on a Kawasaki four stroke fuel injected engine, whether using high compression pistons, cams, or higher ratio supercharger compressor wheels, it will be necessary to increase the fuel flow delivery. The O.E.M. Kawasaki injectors have been precision flow rate tested to be 90 to 95 percent peaked on stock units at sea level without modifications. R&D offers high performance fuel injectors with a higher atomization spray pattern that are easily capable of delivering fuel flow specifications to accommodate up to 375-400 horsepower! R&D has flow rate tested the O.E.M. Ultra 250X injectors and verified them to flow 375cc at 40 PSI of fuel pressure, which rates them to flow 38 pounds of fuel per hour. The R&D High Performance Fuel Injectors have been precision flow rate tested to 625cc at 70 PSI of fuel pressure, which rates them to flow 62 pounds of fuel per hour. R&D High Performance Injectors have been flow rate tested to perform excellent, delivering precise fuel flow at fuel pressure ratings ranging from 40 to 80 PSI. Each R&D high Performance Fuel Injector Kit will come packaged with vital flow test rating information that will be broken down specifically in five pound increments in fuel pressure to give the fuel flow delivery amounts in cubic centimeters and overall pounds of fuel per hour. This fuel pressure/fuel flow table information will help in tuning fuel pressure to match the engines fuel flow needs based on horsepower gains over stock. R&D offers only the highest quality fuel injectors, fuel pressure regulators, and fuel management accessories for all your fuel management needs. R&D NOZZLE WEDGE KIT 141-25001 $68.95 The R&D 1 Degree Reduction Nozzle Wedge Kit for the new KAWASAKI ULTRA 250 will add quicker acceleration and top speed performance as well as allow the ULTRA 250s’ bow to ride slightly higher which will significantly reduce annoying bow spray promoting a much dryer ride. Extensive testing has led our development team to wedge the reduction nozzle up 1 full degree which will inexpensively give the ULTRA 250 better handling everywhere and provide a boost of up to 1 mph in top speed performance. In fact, a much smoother and more predictable ride will be noticed, along with the reduction of annoying bow spray! The billet aluminum CNC machined 1 degree reduction nozzle wedge kit was specifically designed to work without compromising or removing the O.E.M. reverse gate. The R&D Pump Wedge Kit comes complete with all the necessary hardware and instructions for easy installation. A smoother, more enjoyable, dryer, faster ride! R&D POWERSHOT ADJUSTABLE FUEL TUNER 801-25000 $461.92 The R&D Powershot fuel injection tuner will deliver increased horsepower, acceleration, and stronger mid-range performance by delivering a higher performing air to fuel ratio (A.F.R.) to the engine. R&D Performance has tested, documented, and analyzed the O.E.M. fuel map and pre-programmed and coded the new R&D Powershot fuel injection control module to safely alter the O.E.M. fuel map to a higher performing and safer A.F.R. (richer). More horsepower, greater acceleration and stronger mid-range are the result when the proper A.F.R. is achieved and is tuned for optimum performance. The R&D Powershot is fully adjustable on the fly (with the engine running, observed and tuned while riding), and will accommodate a wide range of adjustability to properly performance tune the A.F.R. for any combination of aftermarket parts. The R&D Powershot will add horsepower, reliability, and adjustability to any electronic fuel injected two or four stroke watercraft engine. R&D PUMP SHOE SEAL KIT 161-25000 $69.95 The R&D Pump Shoe Seal kit for the Ultra 250 is now available. The three piece Seal Kit stuffs up the unwanted cavities in the pump shoe and the oem intake grate that aid in producing cavitation. This kit allows you to seal up the area between the intake grate and pump shoe, which will reduce cavitation and increase pump efficiency and performance. R&D RIDEPLATE 121-25000 $229.95  The R&D Kawasaki Ultra 250X Ride Plate has been fashioned after our dominant and championship winning GP-1200R and Kawasaki 15-F ride plate designs with a few new tricks added. The Ultra 250 ride plate is extended 30mm and re-angled over stock to reduce porpoising while the new R&D stepper concept will add top speed. R&D’s Ride Plate concepts are the only aftermarket designs to dominate in Offshore, National, and World Championships, and to be used and endorsed by Factory Yamaha and Kawasaki racing teams for nearly a decade! The new Ultra 250X ride plate from R&D is “The Perfect Ride plate” with a great balance of speed and handling with no compromises! 2-3 MPH top speed improvement Race proven designs for over a decade Unique industry first multi-step concept Improved straight line stability Significantly improved cornering Reduced chine walking on high speed sweepers Drives through chop with superior stability Retains reverse gate mounting and operation   R&D SUPERCHARGER BELT TENSIONER WHEEL 611-25000 $75.95 R&D has significantly improved the Kawasaki Ultra 250’s serpentine belt tensioning wheel system by redesigning and precision machining a new tensioner wheel with a larger O.D. The new R&D Tensioner Wheel offers a wider adjustment range and helps to reduce belt slippage via more surface area for belt contact. Less belt slippage with less belt tension reduces heat and promotes supercharger bearing life! The R&D Tensioner Wheel also offers a perfect adjustment range when installing an R&D Supercharger Wheel. Better adjustment promotes less belt slippage which will add a boost in power. Wheel comes complete with precision bearing installed. R&D SUPERCHARGER WHEEL HUB KIT 611-25001 $79.95 The R&D Ultra 250 Billet Supercharger Wheel Hub Kit was designed and developed while testing the R&D Supercharger 1 to 1 Booster Wheel Kit. The R&D Billet Supercharger Hub Kit will replace the O.E.M.’s vulnerable part with a redesigned and beefed up precision CNC Machined 6061 billet aluminum part that is much stronger than stock. The new R&D design also offers pulley wheel alignment adjustments with a CNC machined Shim Kit that allows for precision serpentine belt cog alignment. The R&D kit comes complete with a special tool that will indicate the perfect alignment of the crank drive and compressor pulleys. At 8,000 RPM, horsepower and belt life can be greatly sacrificed through misaligned pulleys! The R&D Kit offers superior strength, precision pulley alignment, and extended serpentine belt life. This all adds up to a powerful gain. R&D SUPERCHARGER PULLEYS 611-25011 $194.95 Ratio 1 to 1 611-25105 $194.95 Ratio 1.05 to 1 611-25110 $194.95 Ratio 1.1 to 1 The R&D Racing Supercharger Pulley Wheel will deliver a noticeable and impressive boost in torque and overall horsepower. Designed and manufactured from high quality billet aluminum and precision hard anodized for superior belt wear resistance. The R&D Pulley is ¾ lb lighter than the O.E.M. steel pulley, and delivers 2.5 to 3.5 lbs of additional boost pressure along with 30 plus well fed ponies. The holeshot acceleration is a solid 1.5-2 boat lengths over stock with a top speed gain of 1 to 2 mph over stock. Impressive results! The R&D Pulley comes completely assembled with a new high performance bearing, all necessary hardware and installation instructions. R&D SUPERCHARGER WHEEL PULLER TOOL 611-26004 $50.95 The R&D Ultra 250 Supercharger Wheel Puller Tool was developed to offer a much safer and quicker method to extract or pull the compressor wheel from the bearing carrier hub assembly without causing any damage or breakage to the bearing carrier hub. The R&D wheel puller tool makes it fast and easy to remove a supercharger wheel without the removal of the intercooler system or the water muffler assembly. The R&D supercharger drive wheel puller will save at least an hour on a pulley removal and replacement. A must have tool. R&D SURGE AND BLOWOFF VALVE AIR FILTER KIT 215-25001 $64.95 R&D Performance offers a two part High Performance Surge and Blowoff Valve Air Filter Kit which will reduce the engines intake air temperature promoting stronger acceleration and mid range performance as well as better top speed averages. The O.E.M. Surge Protection device recycles wasted off hot air back into the O.E.M. air plenum box whenever there is off and on throttle operations. In aggressive recreational or closed course riding styles, this can promote sluggish acceleration from turn to turn due to the recycled hot air. The R&D Surge Blowoff Filter Kit cycles the hot wasted off air to the back of the hull allowing it to vent out via the rear air vents. The R&D Filter Kit comes complete with 2 port plugs to seal off the blowoff valves return ports on the O.E.M. air plenum box and allowing the recycling hoses to be removed for a great high performance look. • Lowers intake air temperatures • Adds to low end response • Displays a great high performance look • Adds a great high performance sound • A must have accessory for offshore and closed course R&D WASTE GATE BLOCK-OFF KIT 611-26001 $24.95 The new R&D Waste Gate Block-Off kit is designed to block-off the inconsistent OEM waste gate. The cnc machined part allows the supercharger to deliver its boost without premature pressure loss from a leaking waste gate. Kit comes complete with gaskets and hardware. R&D SPONSON KIT 121-25001 $339.95 The new R&D Kawasaki Ultra 250 Pro Series Sponson Kit was designed and developed with all new generation performance concepts in mind to deliver a whole new level of handling and speed performance with offshore and closed course race proven adjustability options. The R&D Pro Series Sponson Kits have been extensively offshore, race track, and 1 and 2 up recreational tested to guarantee a comfortable setting for any riding style or condition! The R&D Ultra 250 Sponson Kit will deliver higher top speed performance and a much smoother and more predictable ride over O.E.M. sponsons. Low speed and high-speed turns are a breeze with new found control. The secret to R&D’s new generation concept is in the backing plate design with an aftermarket first, low pressure, low friction concept that breaks up and relieves speed robbing drag within the sponson’s backing plate channel. The new R&D design staggers the sponson blades fins water trapping area to pick up less water in the front and more in the back. The stagger/step-up concept greatly reduces chine walk in high speed corners, while allowing more rear end grip. There is also a higher end recreational/race setting with enough grip for the best of pro’s! Finally there is an aftermarket sponson kit that really does it all! More top speed due to less drag, less chine walking, racer preferred rear end grip, and unmatched straight line stability. R&D UNIVERSAL FUEL PRESSURE REGULATOR 801-25009 $249.95 Barb Style 801-25010 $249.95 AN Style 801-25011 $16.18 Mounting Bracket Universal bypass fuel pressure regulator for carbureted or EFI fuel systems applications. Base fuel pressure is adjustable from 20 to 60 PSI with high pressure spring (installed). Ideal for carbureted and EFI bypass applications where more flow and superior pressure control are desired. R&D offers two types of fuel pressure regulator set ups. Part # 801-25010 will come completely assembled with #4 fittings ready for R&D custom hoses with #4 AN fittings for a nice high performance hot rod look. Part # 801-25009 will have brass 3/8” to ¼” barb 90 degree fittings installed for use with push on type hose and Otekier style clamps for security. R&D offers high performance Coast Guard approved fuel hose that can be purchased by the foot (PT#611-27502), as well as the Otekier style clamps (Pt#611-27518). The universal type bypass style regulator is capable of handling any fuel pump up to 250 GPH. Replace “Deadhead” regulator performance and experience the full flow volume and rock steady fuel pressure that only a dynamic R&D fuel pressure regulator kit can produce. Available for Sea-Doo, Yamaha, and Kawasaki watercraft. R&D offers a mounting bracket (PT#801-25011) that specifically mounts the fuel pressure regulator on top of the inner cooler. This location allows the R&D custom fuel lines to route perfectly. RIVA BYPASS VALVE UPGRADE KIT RK1750-BPUK $89.95 Easy to install Bypass Upgrade Kit contains all parts necessary to redirect hot air from the engine’s bypass valves and crankcase vent; eliminating power-robbing engine emissions from entering your air intake system. Kit includes fitted K&N filters for bypass & blow-off valves and crankcase vent. Designed to work with both RIVA Pro-Series & Performance Power Filter Kits. RIVA FREE FLOW EXHAUST RK16090 $189.95 Enables you to bypass or remove secondary muffler (weight savings of +10lbs) improving engine performance by reducing back pressure and harmful detonation. Formed aluminum exhaust tube is lightweight and powder coated to resist corrosion. Included billet exhaust tip (also sold separately) with laser etched graphics is anodized to prevent corrosion. High temperature silicone couplers included with installation instructions. RIVA POWER FILTER KIT RK13090 $229.95 Delivers greatly improved acceleration and increased top speed by replacing the restrictive stock intake system. The Power Filter feeds your supercharger with an increased volume of air via a large 4” diameter intake duct and oversized K&N filter element. Ducting is precision formed from a race proven composite that will not conduct heat to incoming air. Includes water-repellent pre-filter. IJSBA legal for all classes. RIVA PRO-SERIES POWER FILTER KIT RK13096 $379.95 Our Ultra 250X Pro-Series Power Filter Kit is a race-bred air intake system that draws cool air from outside your engine compartment delivering awesome performance and eliminating power-robbing heat intake. Air enters the system under the glove box area through an oversized K&N air filter that is protected by a composite cover to prevent water intrusion. Air is fed to the supercharger via a large 4” diameter intake duct. Ducting is precision formed from a race proven composite that will not conduct heat into incoming air. Includes custom formed glove box interior to accommodate intake system & water-repellent pre-filter. RIVA PRO-SERIES SPONSON KIT RK26090 369.95 Delivers a significant improvement over the stock sponsons with superior blade design and backing plate. Includes a bulletproof mounting system that features three anchor points with billet inserts in sponson fins. Backing plate is precision machined from high strength billet aluminum that is anodized to prevent corrosion. Sponson depth is adjustable to control the amount of influence they have on the craft. Easy installation requires no drilling. RIVA PRO-SERIES WATER BOX RK16091 $289.95 Pro-Series Water Box delivers increased horsepower and performance by reducing exhaust restriction and back pressure. Feature lightweight aluminum construction and precise fit. `07 Models: Direct replacement for original water box. Use with RIVA Free Flow Exhaust Kit RK16090. `08 Models: Direct replacement for original water box. Features larger outlet (2-1/4“) compared to stock water box (1-3/4“). Must be used with RIVA Free Flow Exhaust Kit RK16090-08 RIVA PUMP SEAL KIT RK2590 $64.95 Dramatically reduce cavitation and prop spin with our easy to install Pump Seal Kits. Location specific, molded inserts fill the voids in OEM pump inlet shoe that bleed air into pump causing cavitation. Recommended for modified craft using aftermarket intake grates. Includes detailed installation instructions. RIVA RIDEPLATE RK21090 $219.95 Dramatically Improves Top Speed (+2mph) Improves Handling Reduces Porposing Provides Quicker Planing Integrated Reverse Gate Brackets Powder Coated to Prevent Corrosion IJSBA Race Legal RIVA / JETTRIM SEAT COVER RK5-ULTRA-1 $239.95 RED RK5-ULTRA-2 $239.95 BLUE The ultimate racing and recreation covers for your Kawasaki Watercraft. These covers are made with the finest mateials including high-tec Kevlar, ballistic nylons, marine grade canvas and Jettrim's own non-slip naugahyde non-slip traction material. Available in a variety of colors to match your watercraft's paint and graphics scheme. RIVA VALVE COVER BLOCK-OFF KIT RK19090-VCB $39.95 Riva's Valve Cover Block-off Kit is designed to seal off the ports on the valve cover when removing the emission control system for racing applications. There are two major benefits to removing the factory emissions system: 1) For racing applications it is recommended to remove all necessary equipment from your craft for increased reliability and reduced maintenance. This also cleans up plumbing in the engine compartment providing a clean look. 2) To accurately monitor air/fuel ration for tuning purposes you must remove the emissions system. The OEM system pumps fresh air into the exhaust stream throwing off air/fuel ratio. Plates are precision machined from billet aluminum and anodized to prevent corrosion. Includes two block-off plates and installation instructions. SOLAS CONCORD IMPELLER KX-CD 16/21 $289.95 WORX SPONSONS WR536 $289.95 WORX sponsons are extensively tested "on the water" before going into production. Unbelievable cornering, better control in the rough and predictable inline tracking. WORX sponsons are easy to fit, look great and bolt right into stock mounting holes.