Electronic engine testers and adjusters for vehicle ignition and charging circuits and tracing faults, analyzing and measuring the intake vacuums of multi-cylinder vehicle engines and diagnosing faults, measuring the engine speeds of vehicle engines, measuring and analyzing the exhaust gases of vehicle engines, testing lead-acid batteries, charging lead-acid batteries for outboard motors, motorcycle and similar engines, namely, engines of motorized two-wheeled and three-wheeled vehicles, snow...