230 SUPPLEMENT-1981 2250A
Refer to Pgs. 115
Table N19 Carburetor Specifications
Secondary Main Jet
Pilot Air Jet
Primary Main Air Jet
Secondary Main Air Jet
CAMSHAFT CHAIN, GUIDES, TENSIONER
Refer to Pgs. 120
121, noting the following.
Chain guide wear
Table N20 Camshaft Chain Guide Wear
Chain tensioner inspection
Table N21 Chain
Spring Free Length
CYLINDER HEAD, VALVES
Valve seat cutters (special
are newly designed,
procedures are changed a little.
new seat cutters
available for the models before
1981 model. Refer to Pgs. 121
126 noting the follow·
Valve, Valve Guide, Valve Seat
Valve Seat Inspection
The valve must seat in the valve seat evenly around
the circumference over the specified area.
area is too wide, the seating pressure per unit of area is
which may result in compression leakage and
carbon accumulation on the
surface. If the seat·
ing area is too narrow, heat
transfer from the
reduced and the valve will overheat and warp.
seating or seat damage will cause compression leakage.
• Remove the valve, and check to
if the valve and
valve guide are
good condition before valve seat
• Apply machinist's dye to the valve seat, and then use
a lapper to tap the valve lightly into place.
• Remove the valve, and note where the dye adheres to
the valve seating
The distribution of the dye
on the seating surface gives an indication of seat
•If the distribution of the dye shows uneven seating
or seat damage, or if the
or outside diameter of
surface is out of the specified range, repair
the valve seat.
Valve Seating Surface
25 .0 mm
2. Seating Surface (45°)
Inner Surface (60°)
3. Outer Surface (32°)
Valve Seat Repair
A valve seat which requires repair is cut with a set of
valve seat cutters.
Five seat cutters are
complete repair; two 32°; two 45°; and one 60°
cutters, one for the inlet and the other for the exhaust.
When using the cutter, be sure to apply engine
oil to the cutting part before grinding and also wipe
off ground particles adhering to the cutter with washing