Valve Guide Repair
CAUTION:
- Always reface the valve seat after the valve guide has been reamed, and use a suitable scraper to break the sharp corner (ID) left by the reamer at the top of the valve guide.
The interference angle of the valve and seat should not be lapped out. Remove grooves or score marks from the end of the valve stem, and chamfer it as necessary. Do not remove more than 0.254 mm (0.010 in) from the end of the valve stem.
NOTE:
- If oversize valve stems and oversize stem seals are not available, bore out original guide and install service bushing. Ream ID for specified clearance for standard size valve. Reface valve seat as required. Install standard size valve stem seal.
- Use a hand-reaming kit to ream the valve guide.
- Reface the valve seat.
- Clean the sharp edges of the valve guide inner diameter left by reaming.