Reed Valve Assembly - Yamaha MM700A Manual

ENGINE
of the tlzreadedrod next to thepiston. Install
the nut next to the large washer and tighten
it to pull the piston pin into the piston. Do
not use excessive force. I f i f is d/fficult to
move the piston pin, check to make sure the
pin is not catching on the needle bearing in
the connecting rod.
5. Install new piston pin clips (Figure 41). Make sure
they are completely seated in their grooves. The clip
opening must be either directly up or down. The clip
opening must not align with the slot in the piston pin bore
of the piston.
CAUTION
Always install new piston pin clips and
make sure clips snap securely into piston
grooves. A weak or improperly installed clip
could disengage during engine operation
and cause excessive engine damage.
6. Check the installation by rocking the piston back and
forth around the pin. It should rotate freely.
7. Install the bottom piston ring first then the top ring.
Make sure the rings are installedwith the manufacturer's
mark toward the top of the piston. Spread the ends of the
ring carefully with your thumbs and slip the ring gently
over the top of the piston.
8. Make sure the ring(s) are free to enter the groove(s) all
the way around the circumference and the ends are
aligned with the locating pins. See Figure 42.
9. If new components were installed, break in the engine
as if it were new. Refer to Break-In Procedure in Chapter
Three.
REED VALVE
The engine is equipped with a reed valve induction sys-
tem.
and the upper half of the crankcase (Figure 43).
NOTE
The engine is shown removed in thefollow-
is not necessary'.
Five.
2. Remove the four retaining screws, then remove the
carburetor adapter (Figure 44).
3. Lift the reed valve assembly (Figure 45) fi-om the
crankcase.
4. Remove the gasket and clean the residue from the
valve housing and the crankcase.
5. Check the threaded holes
and repair as necessary.
6. Inspect the reed valve assembly as described in this
chapter.
7. Check the condition of the carburetor adapter. The
adapter must seal against the reed valve housing. Leaks
will cause the cylinder to run lean.
ASSEMBLY
the crankcase for damage
in