Group 6 - Mini-Bike/CPR
1. Cylinder head and gasket: 6 bolts, 10mm socket wrench: when tightening the head back on, a torque wrench should be used to a specific torque specified by the manufacturer. But since we did not have one, we tightened them to the best of our abilities. difficulty 2
a. Spark plug: 19mm socket wrench. difficulty 1
b. Spark plug cover + timing mechanism: 2 - 10mm bolts for the timing mechanism: It was difficult to adjust the timing mechanism to the proper position. The mechanism itself is magnetic and it hovers over the magnetic flywheel and is held on by 2 bolts. In order to secure it, you have to hold the mechanism over the magnetic flywheel, which can be difficult. difficulty 4
2. Carburetor and gaskets: 2 – 8mm bolts. The carburetor slides onto 2 rails , with a gasket on the inside and the outside. Since the gaskets were specific to there respective side, it took a minute to figure out which one went where. difficulty 2
3. Air filter: 2 – 8mm bolts. The air filter went on the outside of the carburetor on the same rails that the carburetor slid onto. difficulty 2
4. Throttle assembly: This was the most difficult part of the reassembly process. This was due to the fact that there were 2 springs that attached to the motor in different points, and we referred to pictures to see where they attached. difficulty 5
5. Muffler and gasket: 2-8mm socket wrench: This also includes the muffler cage. One of the springs of the throttle assembly was attached to the muffler cage to keep the assembly in proper tension. difficulty 3
6. Starter assembly: 3-9mm socket bolts: The starter assembly goes on the opposite side of the clutch and flywheel, which turns the motor over. difficulty 2
7. Gas tank and shield: 10 mm , 3 bolts : The shield goes under the gas tank which keeps the heat of the engine from heating up the gas in the tank. We also had to make sure we hooked up the gas line tube from the tank to the engine. difficulty 2
8. Kill switch: The kill switch has 2 wires that attach to the motor at 2 different points. One is a ground that bolts directly to the engine block and the other attaches to the timing mechanism. At this point, all the components that attach to the motor are secured. difficulty 2
9. Rear wheel assembly:
a. Sprocket: 6 bolts, 5mm hex wrench. The sprocket goes on the left side of the wheel and the bolts have to be tightened in a star pattern with a torque wrench. difficulty 3
b. Brake rotor: 6 bolts, 5mm hex wrench. Is secured on the same way as the sprocket in a star pattern. difficulty 3
c. There are 2 different size spacers. The larger of the 2 goes on the left side, or the drive side, while the smaller of the 2 goes on the right. difficulty 3
d. There is a 14mm bolt that is secured on with a lock nut. difficulty 2
10. Steering wheel & handlebar assembly:
a. A large 14mm bolt goes through the top of the assembly and is secured on by a 16 mm nut on the bottom of the headset. difficulty 1
b. The brake lever is reattached using a 5mm hex wrench and the cable is fed through at the top of the handle. difficulty 2
c. The throttle is attached to the right side of the handle bars and is secured using a 3mm hex wrench. difficulty 2
d. Rear fender: There are 2 bolts with rubber washers that attach the fender on. The rubber washers go in between the mounts and the bolts to prevent chattering noise when the fender is vibrating. difficulty 1
11. 2 Chain Guards: the chain guards cover the path of the chain for the safety of the rider. The rear chain guard goes on first, and then the front chain guard overlaps it. difficulty 2
12. Seat: There are 3 – 10mm bolts that secure the seat. difficulty 2
*Note: the break down for the difficulty levels are as follows:
1 = easy, requiring no real thought or awkward positioning, small time span(1-2 minutes).
ex screwing a single part that is fully exposed such as the spark plug.
2 = medium, a few fasteners some dexterity required, small time span(1-2 minutes).
ex screwing more than two bolts with the bolts not fully exposed such as the combustion chamber dissection.
3 = hard, many fasteners some requiring dexterity, small to medium time span(1-10 minutes).
ex screwing multiple bolts which are significantly hard to get to, such as the carburetor assembly
4 = hard, many fasteners most requiring dexterity or strength,medium time span(3-10 minutes).
ex the locking collar which required a great deal of dexterity and patience to put back on
5 = frustrating, a great deal of patience and dexterity required, long time span(15 minutes +).
ex the throttle assembly.
Post Reassembly analysis
Reassembly Process note
All the same tools were used to reassemble the product as were used in its dissassembly
End Result of Reassembly notes
After Reassembly the bike no longer works. The problem with the bike appears to be related to the throttling assembly which unfortunately no longer function properly due to the fact that at one of its pivot points it is missing a piece to hold it on. To correct the problem our group looped a metal ring through the throttle assembly and the pin on that pivot to prevent the throttling device from popping off, resulting in partial functionality. To make this throttle assembly more robust decreasing the number of springs and pivot points would suffice.
Product Recommendations Our main recommendation concerning the product given our trouble with the reassembly is to make the throttling assembly more robust.