P 13/ 14
Repair
[4]DISASSEMBLY/ASSEMBLY
[4]-14. Engine block (cont.)
ASSEMBLING
(1) Piston can be assembled in either direction.
Apply Makita grease N No. 2 to the needle bearing of Crank shaft assembly in advance.
(2)Insert Piston pin through Piston and Crank shaft, and fix it with Clips by using the awl (Clip has no direction).
(3)Piston rings have their directions and each different shapes as drawn in Fig. 63.
First, install Piston ring 34, and next, install Piston ring (second) 34, then finally install Piston ring (top) 34. The piston ring 34 for the lowest groove on Piston consists of three part; top ring, middle ring and bottom ring. Top ring and bottom ring have a clearance and the distance of each clearance point must have 120° angle. Piston ring (top) 34 and Piston ring (second) 34 consist of single part and the distance between their clearances must have 180° angle when they fixed into the grooves on the piston.
Note: Piston rings are easy to break. Do not enlarge them too much when fixed.
(4)Assemble Cylinder block assembly.
After removing grease from the matching surface of Cylinder block and Crank case (Refer to Fig. 64), apply ThreeBond 1216 on the Crank case side.
Note: The layer of ThreeBond 1216 has to be thin so as not to enter into the oil route in Engine and get clogged. Apply
While holding Piston rings, install the assembled part of Piston into Cylinder block.
(5)Fasten Cylinder block assembly by tighten the screws in crisscross pattern.
Fig. 63
Piston ring (top) 34
The position between two | Piston ring (second) 34 | |
clearances must be | ||
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at 180° opposite point. |
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| Difference of the clearance | Piston ring 34 |
| Piston top end | should be 120°. |
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| Piston ring (top) 34 |
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Top layer |
| The center is expanded. |
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| Piston ring (second) 34 |
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Middle layer |
| The bottom is wider than the top. | Piston |
Bottom layer |
| Piston ring 34 for the lowest groove on Piston |
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| Cross section of Piston | consists of three layers. |
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| The top layer and the bottom layer have a clearance |
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as drawn above. Clearances should not be overlapped each other.
Fig. 64
