Description
Overview:
This oversize valve stem is a precision replacement part for Villiers MK12 and C12 small engines used on classic garden and light construction machinery. Made from hardened, precision-ground steel, it is manufactured to .005 inch oversize (0.127 mm) to match reworked valve guides and restore correct running clearance. Fitting an oversize stem helps reduce valve wobble and oil consumption, supporting stable compression and smoother operation on engines that have seen guide wear. Supplied as unused vintage old stock, it remains fully serviceable and may show light storage tarnish that does not affect performance. Ideal for engine repairs and restorations where factory dimensions need to be reclaimed without replacing the entire cylinder head or guide assembly.
Key Features:
- .005 inch (0.127 mm) oversize stem to suit reamed valve guides and recover correct clearances
- Hardened, precision-ground steel for durability and smooth movement in the guide
- Direct replacement for Villiers MK12 and C12 engines for straightforward identification
- Helps restore compression and reduces valve side-play on worn engines
- Unused vintage old stock (NOS); may show light tarnish from long-term storage
- Smooth stem finish to limit friction and wear during operation
- Consistent dimensions along the stem for reliable seating and alignment
- Suitable for repair and rebuild work on classic Villiers-powered machines
Typical Applications:
Used during top-end overhauls, routine rebuilds, and restorations where valve guides have been reamed to accept an oversize stem. Common on ageing Villiers-powered mowers, rotavators, pumps, generators, compact construction equipment, and other small plant where maintaining correct valve-to-guide clearance is essential for easy starting, stable idle, and reduced oil usage.
Also known as:
Oversize engine valve stem 0.005 in (0.127 mm), OS valve stem, valve shank (oversize), replacement valve stem for Villiers small engines, MK series oversize stem.
Fits Models:
MK12, C12
