How to Change the Oil in a Honda CRF 70by Chris Gilliland
The CRF 70F hails from a long line of mini dirt bikes produced by the Honda Motor Company, serving as an entry-level machine for younger riders to cut their teeth on. Keeping this dirt bike in working order involves a small amount of maintenance, mostly in the form of engine oil changes, every 600 miles or six months, whichever comes first. The process is similar to changing a car or truck's oil. However, the CRF 70F's engine uses a cleanable oil screen to filter out debris within the oil, in place of a disposable filter element.
Start the CRF 70F and take it for a short, 5-minute ride. Stop the engine and support the motorcycle on its kickstand. Let the engine cool for another 5 minutes.
Wipe the area around the oil cap, located on the right side of the engine, with a damp shop towel to remove any dirt or dust. Unscrew the oil cap and its attached dipstick from the engine by hand.
Unscrew the drain plug from the bottom right side of the engine crankcase, using a 17 mm socket and socket wrench. Drain the engine oil into a drain pan. Rock the motorcycle from side to side, once the oil flow has reduced to a light trickle.
Pull the sealing washer off of the drain plug threads. Clean the drain plug with a parts cleaning spray, then slip a new sealing washer over the drain plug thread. Screw the drain plug into the engine crankcase by hand, then tighten the drain plug to 18 foot-pounds with a torque wrench.
Unscrew the bolts from the perimeter of the right engine crankcase cover, using a 10 mm socket and a socket wrench. Pull the cover away from the engine crankcase cover to reveal the clutch assembly. Pull the oil screen out from below the clutch assembly by hand.
Spray the oil screen with a parts cleaning spray to remove trapped debris from the screen mesh. Wipe away remaining particles with a shop towel. Push the oil screen into the engine, facing the tapered side of the screen inward.
Reinstall the right engine crankcase cover. Tighten the cover mounting bolts to 7.5 foot-pounds, using a 10 mm socket and a torque wrench.
Pour a half-quart of 10W-40 engine oil into the engine through the oil cap filler neck. Wipe away any spilled oil, then screw the oil cap into place.
Start the motorcycle and let it idle in place for 3 minutes, allowing the oil to circulate through the engine. Stop the engine and let the oil settle for another 3 minutes.
Unscrew the oil cap by hand, then wipe its dipstick clean with a shop towel. Insert the dipstick into the engine until the oil cap is resting against the top of the filler neck, then pull the dipstick out. Add 1 to 2 oz. of 10W-40 engine oil into the engine, if the oil level reading is below the upper level mark imprinted into the dipstick. Wipe the dipstick clean, then screw the oil cap tightly into place by hand.