GENUINE HONDA & YUMINASHI TUNING PARTS FOR HONDA TRX90 SPORTRAX 90 (1993 - SEPTEMBER 8, 2005)
Honda TRX90 ATV Specs and Features (1994 – SEPTEMBER 8, 2005):
Engine: It is brought to life by a longitudinally installed four-stroke, air-cooled single-cylinder OHC engine. It has a bore-stroke ratio of 47 x 49.5 mm, and the engine displacement is 85.8 cm3 (5.23 in3) delivered by a 16-mm piston-valve carburetor. The compression ratio is 9.2:1. It has a forced pressure and wet-sump lubrication system with urethane-foam-and-screen air filtration. The standalone engine weight is 43.7 lbs/19.8 Kg, and the fuel tank capacity is 1.58 US gallons/6 liters with a 0.34-gallon reserve.
Ignition: It originally has a recoil pull-rope starter and CDI ignition system, which changed to DC-CDI (Capacitor Discharge Ignition) electric starter system beginning 2006. It requires an NGK CR7HSA / Nippon-Denso U22 FSR-U spark plug and a 12V 4Ah 80-CCA (Cold Cranking Amps) battery with assembled dimensions of 4.40 x 2.75 x 4.25 inches (112 x 70 x 108 mm – L x W x H), not including wire harness or mounting accessories.
Drivetrain: A four-speed transmission, wet, multi-plate centrifugal semi-automatic clutch, and chain-and-sprocket setup bring power to the wheels. The primary reduction is 4.058 (69/17), and the final reduction is 3.846 (50/13). Its gearshift is left-foot-operated and has an N-1-2-3-4 pattern. The quad features a keyed ignition switch for added security and an adjustable throttle limiter for younger riders.
Lubrication:Oil capacity at disassembly is 0.75 US quarts/0.71 liters. Use Honda GN4 4-stroke oil or its equivalent with an API service classification of at least SJ for best results. Avoid using variants with friction modifiers or additives as these can cause engine and Honda TRX 90 parts damage. Recommended viscosity is SAE 10W-40, but you may use SAE 5W, 10W-30, 20W-40, or 20W-50, depending on the ambient temperature.