Nanni N4.40, Workshop Manual

Page: 146 / 175

ENGINE
03-M-E3B, 03-M-DI-E3B, 03-M-E3BG, WSM
1-S76
Valve Recessing
1. Clean the cylinder head surface, valve face and valve seat.
2. Set the valve into the valve guide.
3. Measure the valve recessing with a depth gauge.
4. If the measurement is more than the allowable limit, replace the
valve.
5. If it stays more than the allowable limit after you replace the
valve, replace the cylinder head.
M00000003ENS0108US1
Valve recessing
Factory
spec.
D1503-M,
D1703-M,
D1803-M,
V2003-M,
V2203-M,
V2403-M,
V2403-M-T,
D1703-M-BG,
V2003-M-BG,
V2003-M-T-BG,
V2203-M-BG,
V2403-M-BG
0.05 (protrusion) to
0.15 (recessing) mm
0.002 (protrusion) to
0.0059 (recessing) in.
D1803-M-DI,
V2403-M-DI,
V2403-M-DI-T
0.65 to 0.85 mm
0.026 to 0.033 in.
Allowable
limit
D1503-M,
D1703-M,
D1803-M,
V2003-M,
V2203-M
V2403-M,
V2403-M-T,
D1703-M-BG,
V2003-M-BG,
V2003-M-T-BG,
V2203-M-BG,
V2403-M-BG
0.40 (recessing) mm
0.016 (recessing) in.
D1803-M-DI,
V2403-M-DI,
V2403-M-DI-T
1.20 mm
0.0472 in.
(1) Cylinder Head Surface (A) Recessing
(B) Protrusion
KiSC issued 06, 2009 A