Honda TRX420TM Owner's Manual page 215

Capacities
passenger capacity
maximum weight
capacity
Engine Specifications
displacement
bore & stroke
compression ratio
spark plug
(standard)
valve clearance
(cold)
spark plug gap
idle speed
operator only
220 kg (485 lbs)
rider, all cargo and accessories
420.2 cm (25.63 cu-in)
86.5 71.5 mm (3.41
9.9 : 1
BKR5E-11 (NGK)
or K16PR-U11 (DENSO)
0.15 mm (0.006 in)
intake:
exhaust: 0.23 mm (0.009 in)
1.00 1.10 mm (0.039 0.043 in)
1,400 100 min (rpm)
(NO ADJUSTMENT)
Technical Information
Specifications
2.81 in)
205