26 SHIFT LIGHT INDICATORS TO SCAN AND SIGNAL OPTIMUM SHIFTING SPEEDS FOR INTERNAL COMBUSTION ENGINES; R.P.M. LIMITERS FOR SENSING, CONTROLLING AND STABILIZING ENGINE SPEEDS OF INTERNAL COMBUSTION ENGINES; TACHOMETERS; TACHOMETERS WITH SHIFT LIGHT INDICATORS; TACHOMETERS WITH SHIFT LIGHT INDICATORS AND R.P.M. LIMITERS; AND INFRA-RED OPTICAL SCANNERS, ALL FOR USE WITH INTERNAL COMBUSTION ENGINES