Cylinder - Yamaha MM700A Manual

102
rial from the cylinder head mating surface will
change the compression ratio and clearance of the
squish area around the outside edge.
4. Check the cylinder head water passages for coolant
residue and sludge buildup. Clean passages thoroughly
with solvent and allow to dry thoroughly.
5. Wash the cylinder head in hot soap and water and rinse
thoroughly before installation.

CYLINDER

The aluminum cylinder has a coated bore. Install new
standard size parts if the cylinder or piston is worn beyond
limits or otherwise damaged.
Refer to Figure 12.
Removal
1. Remove the cylinder head as described in this chapter.
2. If the engine is installed in the frame, remove the muf-
fler and exhaust pipe as described in Chapter Five.
3. Unbolt and remove the exhaust manifold from the cyl-
inders.
ter Five.
5. Gradually loosen the four flange nuts (Figure 19) se-
curing each cylinder to the crankcase in a crossing pattern.
Then remove the nuts.
NOTE
Ifreusing the cylinder, reinstall it in its orig-
inal position even though the cylinders are
identical. Mark the cylinder with its loca-
tion before removal in order to reinstall it in
the proper location. Also mark the original
piston so it can be used in the same cylinder,
a
unless new piston is installed.
stroke, then pull the cylinder straight up, away from the
piston, and remove it.
7. Repeat the procedure for the remaining cylinders.
8. Remove the cylinder base gasket.
9. Cover the openings in the crankcase around the con-
necting rods with clean rags to keep dirt and loose parts
from entering the crankcase.
Inspection
Cylinder measurement requires a precision inside mi-
crometer or bore gauge. If the right tools are not available,
have the dealership or a machine shop measure the parts.
1. Remove all gasket residue from the bottom gasket sur-
face.
2. Clean the top of the cylinder carefully. Do not scratch
the sealing surface.
3. Clean all gasket residue from the exhaust manifold
sealing area of the cylinder.
4. Use a soft scraper or a wire brush to remove all carbon
deposits from the exhaust port.
CAUTION
When cleaning the exhoz~stport in Step 5, do
not allow the wire brush or scraper to slip
inside the cylinder and damage the cylinder
bore. Be especially careful when using
power equipment, such as a rotating wire
brush and an electric drill.
5. Wash the cylinder with hot soapy water, then rinse with
water to remove loose dirt and carbon particles before
measuring the cylinder bore. Measurements may be in-
correct if the cylinder is not cleaned thoroughly.
6. Measure the cylinder bore diameter as described under
CHAPTER FOUR