TOHATSU NB-1000 Service Manual page 114

SECTION 4
Preliminary
1. Before instaIIation, lightly coat the outside surfaces of
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new bearing seals and o-rings with genuine engine oil or TC-
W3 oil. Apply bearing cup grease to the seal lips. Press fit the seals
into place using an appropriate size seal installer to avoid
damaging the seal or component.
• lnstaII a new oil seal in lower crankcase head and a new o-ring
on base of lower crankcase head (or engine base or lower cowl).
• Install new oil seal (1) in upper magneto base and new o-ring (2).
2. Coat the rotating surfaces of the crankshaft and connecting rod
bearings, bearing washers, and bearing thrust plates (model 40)
with genuine engine oil or TC-W3 oil.
Crankshaft
3. If upper main bearing was removed, slide and install the
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upper main bearing onto crankshaft (6).
4. lf lower main bearing was removed, coat lower end of crankshaft
with genuine engine oil or TC-W3 oil and install the bearing.
Pistons
5. Install each piston ring in its original groove on its original
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piston using the piston ring tool (Part No. 353-72249-0).
Each ring must be installed so end notches (11) fit the contour of
piston knock (12) when the ring is compressed.
6. Install each piston on its respective connecting rod as
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follows:
An arrow (13) or the word "UP" is cast on the top of
the piston. This mark is used to align the piston in a
specific orientation. See chart for proper orientation.
2.5/3.5 Arrow (Crown Mark) points to exhaust port
5 "Up" mark points to flywheel
8/9.8 "Up" mark points to flywheel
9.9/15/18 "Up" mark points to flywheel
25/30 "Up" mark points to flywheel
40 "Up" mark points to flywheel
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NOTE
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T2024
T2029
T1696
T2030
1-/ 2-Cylinder