Hercules — Valve Tappet Adjustment
Adjustments · valve tappets
From a Hercules owner's manual — check it applies to your exact model before use.
Procedure
- Crank the engine until the intake valve of No. 1 cylinder just starts to open; adjust the tappets on No. 4 cylinder (No. 6 in a six cylinder engine).
- Crank the engine until the exhaust valve of No. 2 cylinder just closes and the intake valve of No. 2 just starts to open; adjust the tappets on No. 3 cylinder.
- Crank the engine until the valves of No. 4 cylinder are in that position and adjust the tappets on No. 1 cylinder.
- Crank the engine until the valves on No. 3 cylinder are in that position and adjust the tappets on No. 2 cylinder.
- Install the cylinder head cover and any other parts removed.
- Fill the cooling system, start the engine and warm up to operating temperature.
- With the engine idling slowly, readjust the tappets to the correct operating clearance.
Tools required
- Feeler gauge Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Valve tappet clearance exhaust .010
- Valve tappet clearance intake .010
Source: Hercules owner's manual. Steps and values are as documented; always cross-check against the official manual and any later revisions for your exact serial number before servicing.