Honda TRX420TM Owner's Manual page 90

Riding Your ATV
Crossing Hills or Slopes
To maintain balance and stability when riding across a slope, you
need to shift weight toward the uphill side of the vehicle. To do this,
move your body off the centre of the seat and lean toward the uphill
side.
On a slippery or loose surface, you may also need to steer slightly
uphill to maintain a straight course across the slope.
Avoid crossing hills that are excessively steep, slippery or rough.
Making Turns on Slopes
Compared to riding on level ground, you may need to shift more
weight and lean more when making turns on slopes.
Do not make turns on any slopes until you have first mastered the
techniques for making turns on level terrain.
Basic Operation & Riding
80
Shift weight uphill when crossing slopes.