Parts Diagram | ## | Part # | Description | Qty | Notes |
| 1 | 0387284 | Piston assembly, Std | 3 | |
1 | 0387285 | Piston assembly, .020 o. s | 3 | |
1 | 0387286 | Piston assembly, .030 o. s | 3 | |
2 | 0385807 | Ring set, Std | 3 | |
2 | 0385808 | Ring set, .020 o. s | 3 | |
2 | 0385809 | Ring set, .030 o. s | 3 | |
3 | 0553556 | Screw, crankcase head mtg | 4 | |
4 | 0317831 | Retaining ring | 6 | |
5 | 0388595 | Needle bearing assembly | 3 | |
6 | 0387283 | Connecting rod assembly | 3 | |
7 | 0308186 | Screw, rod cap | 2 | |
8 | 0388188 | Retainer, rod bearing | 3 | |
9 | 0387142 | Needle set, rod bearing | 3 | |
10 | 0390900 | Roller bearing assembly. models with "M" model number suffix only part numbers new for this model year | 1 | |
10 | 0383955 | Roller bearing assembly. models with "H" model number suffix only | 1 | |
11 | 0321895 | Seal, crank shaft | 1 | |
12 | 0313754 | O-ring, upper bearing | 1 | |
13 | 0307480 | Key, flywheel | 1 | |
14 | 0317160 | Crank shaft | 1 | |
15 | 0310433 | Split sleeve, center bearing | 2 | |
16 | 0378252 | Retainer & needle assembly | 2 | |
17 | 0379258 | Bearing assembly | 1 | |
18 | 0305132 | Retaining ring | 1 | |
19 | 0308876 | O-ring, crankcase head | 1 | |
20 | 0385835 | Crankcase head assembly | 1 | |
21 | 0321668 | Seal | 1 | |
22 | 0320954 | Wrist pin | 3 | |