Riva Stage 1

This modification utilizes stock exhaust system with catalytic converter in place. Stock flame arrestor case is retained, but internal screen and forward mounted plenum chamber are removed. We do not recommend the use of aftermarket flame arrestors in conjunction with stock exhaust system with catalytic converter. Our testing has proved that heat produced by the catalytic converter can cause engine damage when stock flame arrestor is removed. Stock oil injection system can be retained.

No internal carburetor modifications are performed. "Tamper Caps" are removed from high and low speed carburetor adjustment screws to optimize carb settings.

Riva Stage 2

RIVA GP1200R Flame Arrestor Kit is installed to increase airflow to motor. No internal carburetor modifications are performed. "Tamper Caps" are removed from high and low speed carburetor adjustment screws to optimize carb settings.

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.

RIVA GP1200R Performance Cylinder Head Kit

 

$369

$222