The crankcases should be assembled with
the engine upside down.
Set the upper crankcase half on wood
blocks to protect the cylinder studs.
1. In the upper crankcase half, check that the 2
crankcase dowel pins (A, Figure 136), 2
transmission bearing alignment 1/2 rings (B), 2
transmission dowel pins (C) and the oil passage
plug (D) are in place.
2. Check that the starter idler gear is installed
in the upper case half with the smaller sprocket
pointing to the alternator side of the engine
(Figure 137). Install the circlip on the idler gear
3. In the lower crankcase half, check that all oil
passages are clear and that the 2 oil control
nozzles are in place (Figure 138).
4. Install the main bearing inserts in the upper
(Figure 130) and lower (Figure 131) crankcase
halves. Make sure their locking tabs are seated
in the notches.
the old inserts are reused, be sure they
are installed in their original positions to
prevent rapid wear.
5. Install new left- and right-hand oil seals on
the ends of the crankshaft (Figure 139); apply
high temperature grease to the seal lips. The
arrow on the seal (A, Figure 140) must face out
and must point in the direction of crankshaft
rotation (clockwise when viewed from the
right-hand side of the engine). The left-hand
crankshaft seal (B, Figure 140) has a narrower
body than the right-hand seal (C).
6. Oil the main bearing inserts and crankshaft
7. Position the cam chain and primary chain
on the crankshaft.
8. Install the crankshaft assembly with
primary chain and cam chain in the upper
crankcase half (Figure 141). The oil seal ribs
must fit into the grooves in the crankcase
9. Put the thrust washer inside the starter
clutch and turn the starter clutch gear while
pushing it into the clutch and roller assembly.
Install the starter clutch/secondary sprocket
through the primary chain (Figure 143).
10. Install the transmission shafts in the upper
crankcase half; see Transmission Gears in
Chapter Six. Align the transmission gears in
the NEUTRAL position (Figure 144).
1 1. Rotate the shift drum to the NEUTRAL
position (Figure 145).
12. Transmission test: This is an optional
procedure to make sure the transmission has
been assembled properly.
a. Carefully place the lower case half in
position, fitting the shift forks in their
proper gear grooves.
b. Seat the upper case half onto the lower
and tap lightly with a plastic or rubber
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