Yanmar 1GM User Manual page 90

84
Scale
/
Connecting Rod Bc arin~ Clea ra nce Measurement
I. Place the connecting rod and uppe r bearing half o n the
connecting rod journal.
2. Cut a piece ofPlastigagc the width of the bearing
( "' i~­
ure
43).
Place the Plastigagc on the journal. then install
the rod cap and bearing. Be sure to install me cap so the
marks on the ca p and rod arc on the same side (Figu re.U ).
,VOTE
Do not place
Pla_~/iKage
owr the joumaloil
hole.
3. Tighten the connecting rod cap to the specification in
Table 2. Do not rotate the cranks haft while the Plastigagc
is in place.
4. Remo ve the
connect ing rod
cap. To de term ine bea ring
clearance. compare the width of the llattcncd Plasugagc
to the markings on the envelope
(F i~ u n'
45). If the cle ar-
anc e is excessive, have the crankshaft reground and install
undersize bearings.
CHAPTER FIVE
Second
ring
12{)°
To p
ring
Piston/Connecting Rod Installation
1. Rotate the crank shaft so the crankpin is at bottom dead
ce nter.
2. Make sure the ring gaps are positioned as she .....n in
Ffgurc 46 .
3. Imm erse the entire piston in clean engine o il. Coal the
cylind er wall with oi l.
4 . Install a piston ring com pres sor around the piston
nn gs.
CAU TION
Use extreme
C1II1'
in Step
5
to prevent the
connecting rodfrom nicking the crankshaft
journal.