John Deere Utility Tractor 420

Lubricate Air Cleaner (10 Hours)

Lubricate 3-Point Implement Attachment (60 Hours)

Check Transmission-Differential

Sign off on the 120 Hourly Maintenance

Lubricate Transmission-Differential

Sign off on the lubrication process

Warning: This procedure requires trained personnel with PPE!

Is the carburetor clean and free of debris?

Enter the initial position of the adjusting needle

Adjust the idling of the tractor

Enter the final position of the adjusting needle after idling adjustment

Adjust the fuel flow into the carburetor

Enter the initial position of the load adjusting needle

Enter the final position of the load adjusting needle after fuel flow adjustment

Does the engine run smoothly after adjustments?

Adjust distributor points as described on page 47.

Loosen screw and turn cover from timing hole located on flywheel housing on distributor side of tractor.

Remove spark plug from No. 1 cylinder (front plug).

Crank engine slowly, keeping spark plug port covered with thumb to find compression stroke of No. 1 cylinder. Compression stroke will be noted by considerable pressure of air on thumb.

Continue to crank slowly until "SPARK" mark on flywheel lines up with marks on timing hole.

With distributor cap and dust cover removed, install rotor and turn rotor counter-clockwise as far as possible. While holding rotor in this position, rotate distributor body slowly until points are just beginning to open.

To determine when points are just beginning to open, remove coil-to-distributor wire from distributor cap and place terminal of wire about 1/8-inch from a grounded part of the tractor. With ignition switch turned on and all parts of ignition system connected, a spark can be seen between the terminal and the ground just as the points open.

Position distributor retainer clamps so they are in clamping position on distributor flange. Tighten two retainer clamp cap screws snugly (but do not deform clamps) to prevent movement of distributor while tractor is operating.

Replace cover plate on distributor body. Install rotor and distributor cap. Install all cables, being sure they make good contacts at distributor, at spark plugs, and at coil terminals. See that terminals of distributor and coil are fully covered by rubber nipples.