RIVA / Boyesen Reed Stuffers are installed into stock reed cages with stock reed petals. Stuffers increase fuel / air velocity through intake tract, resulting in increased throttle response and acceleration. "Tamper Caps" are removed from high and low speed carburetor adjustment screws to optimize carb settings. No internal carburetor modifications are performed.

RIVA Performance Cylinder Head is installed. Head features 41cc domes (including OEM gasket volume) producing 145-150 psi compression (valves down). Girdled head design securely clamps cylinder down preventing potential cylinder cracking possible on modified motrs. Requires use of 92+ octane pump fuel.

Note: RIVA also offers a modification service for your stock cylinder head. This consists of decking and redesigning the combustion chambers. This modification will produce performance similiar to the RIVA Performance Head, but does not provide protection from cylinder cracking.

RIVA Cat Removal D-Plate is installed in place of restrictive catalytic converter increasing top-end speed while reducing under-hood operating temperatures and allowing the use of regular 2-stroke oils. Our D-plate is a high quality stainless steel replica of the plate that is standard equipment on export model Yamaha watercraft without emission controls.

RIVA Cat Temp Sensor Chip is installed to prevent warning lights & beepers from activating when catalytic converter is removed.

RIVA GP1200R Free Flow Exhaust Kit is installed. Kit replaces restrictive sound suppression system located between waterbox and hull exit reducing backpressure and engine operating temperatures.

RIVA GPR Pump Seal Kit is installed. Location specific molded inserts are siliconed into the voids of the OE pump inlet shoe significantly reducing cavitation.

The RIVA / Solas 13/20 ‘Set-Back’ is a special series of performance impellers offered exclusively by RIVA and RIVA authorized dealers. Built by Solas, these impellers deliver the ultimate in performance for most GP1200R1300R applications. Inner hub is machined allowing impellers to mount closer to vein housing for reduced cavitation and more top speed. All three blades are digitally calibrated to RIVA’s uniform pitch specifications. Impellers are then dynamically spin-balanced at high RPM. A precision factory blueprinting process is performed far exceeding any ‘prop shop’ services available. Includes RIVA Billet Impeller Cone for maximum performance and durability

RIVA Performance Pump Cone is installed in place of stock pump cone on jet pump vein housing. Performance Pump Cone significantly reduces cavitation due to its innovative design and asymmetrical shape that matches the angle of stock Yamaha pump nozzle.

RIVA GP1200R Ride Plate and GP1200R Top Loader Intake Grate are installed. Our rideplate and intake grate combo increase top speed and significantly enhance handling characteristics. Prop spin and cavitation found with the stock grate is greatly reduced along with the modified GPR's tendency to drop on its nose when the throttle is let off at high speeds.

RIVA GPR Performance Trim Tabs are installed in place of original trim tabs. Designed to trim craft up for increased top speed and serve as a quick fix to unwanted proposing. Tabs are 2.5 inches longer than stock.

RIVA GPR Pro-Series Adjustable Sponsons are installed. Sponsons dramatically improve the handling of the GPR with a superior blade design and mounting angle. Sponson depth is adjustable to accommodate riding style.

NOTE: Stage II modification is for competition use only.