Takeuchi TB014 Werkstatt-Handbuch Seite 424

SM-E2B SERIES, WSM
Correcting Valve and Valve Seat
A Before correcting the valve and seat, check the valve
stem and the I.D. of valve guide section, and repair them
if necessary.
A After correcting the valve seat, be sure to check the valve
recessing.
1) Correcting Valve
1. Correct the valve with a valve refacer.
Valve face angle Factory spec.
2) Correcting Valve Seat
1. Slightly correct the seat surface with a 0.785 rad (45 ) valve
seat cutter (Code No. 07909-33102).
2. Fitting the valve, check the contact position of the valve face
and seat surface with prussian blue. (Visual check) [ If the
valve has been used for a long period, the seat tends to come
in contact with the upper side of the valve face.]
3. Grind the upper surface of the seat with a 0.262 rad (15 )
valve seat cutter until the valve seat touches to the center of
the valve face (so that (a) equals (b) as shown in the figure)
4. Grind the seat with a 0.785 rad (45 ) valve seat cutter again,
and visually recheck the contact between the valve and seat.
5. Repeat steps 3 and 4 until the correct contact is achieved.
6. Continue lapping until the seated rate becomes more than 70
% of the total contact area.
Valve seat angle Factory spec.
(1) Valve Seat Cutter
(A) Check Contact
(B) Correct Seat Width
(C) Correct Seat Surface
(D) Check Contact
Valve Lapping
1. Apply compound evenly to the valve lapping surface.
2. Insert the valve into the valve guide. Lap the valve onto its
seat with a valve flapper or screwdriver.
3. After lapping the valve, wash the compound away and apply
oil, then repeat valve lapping with oil.
4. Apply prussian blue to the contact surface to check the seated
rate. If it is less than 70 %, repeat valve lapping again.
A When valve lapping is performed, be sure to check the
valve recessing and adjust the valve clearance after
assembling the valve.
S-60
DIESEL ENGINE
0.785 rad
45
0.785 rad
45
(a) Identical Dimensions
(b) Valve Seat Width
(c) 0.262 rad (15 )
(d) 0.785 rad (45 )
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