Service Manual

8-8
Table of Contents
Twin Cylinder Engine Service Manual
February 2017 - Digital Edition
ENGINE INSPECTION AND RECONDITIONING
Upper End Inspection and Reconditioning (Cont.)
Valve Seat Reconditioning (Cont.)
3. Make a nal light pass with a 45-46° cutter to remove any possible burrs at the edges of the seat.
4. After resurfacing the seats, inspect for even valve seating.
5. Refer to “Valve Face Contact Test,” chapter 8, page 8-5.
NOTE: Replace the valve if not making full contact.
6. Repeat valve seat cutting for all seats.
Valve Reconditioning (Lapping)
1. Perform valve lapping if any of the following were performed (Figure 5):
-New valve
-Reground valve
-Valve seat was reconditioned
2. Use a hand valve-lapping tool with suction cup end. Attach suction cup to the end of valve.
3. Apply a light coat of valve grind compound to the valve face.
4. Insert the valve into the matching valve guide.
5. Rotate valve on the seat with tool until a smooth surface is on the valve face and valve seat.
NOTE: Wipe clean any excess compound. Immediately clean any compound on the valve stem, guide, etc.
6. Repeat lapping for all valves.
Figure 5