BOMBARDIER Johnson 90 Service Manual page 47

PERIODIC MAINTENANCE
MAINTENANCE ANO
TUNE-UP PROCEDURES
5. Rotate crankshaft counterclockwise to bring cam nose
vertical to shim surface.
6. Measure tappet clearances by inserting thickness gauge
between cam and shim surface.
Tappet clearance (cold engine condition):
IN.: 0.23 - 0.27 mm (0.009 - 0.011 In)
EX.: 0.23-0.27 mm (0.009-0.011 in)
~ Thickness gauge
l•CAUTION
1
This is a left hand (LH) rotation powerhead. Rotate
crankshaft counterclockwise to prevent water pump
lmpeller damage.
NOTE:
• Rotate crankshaft and measure clearance for each tappet
respective/y by bringing cam nose vertical to shim surface.
• Ali tappet clearances can be measured during two turns of
crankshaft.
7. lf out of specification, adjust tappet clearance by chang­
ing shim.
ADJUSTMENT
Tappet clearances are adjusted by replacing tappet shim.
1. Glose valve and turn tappet cutaway toward inside as
shown in figure.
2. Rotate crankshaft to open (lift up) valve and then remove
camshaft housing bolts where shim is to be replaced.
3. lnstall special tool with camshaft housing bolts as shown
in figure.
éil
5034226: Tappet holder
CD
Cut sectlon of tappet
®Plughole
@Shim
2-11