Supplies:
- Crankshaft
- Bearings and seals
- Liquid or paper carter gasket
- 650 degrees hair dryer (available at hardware stores such as Praxis or Gamma, affordable)
- Tools and torque wrench
- Two equal blocks of wood from the same height
- Plastic hammer (no iron hammer)
- 2-stroke oil
- Heat -resistant gloves
We do not use a gas burner to heat the carter parts, because it does not heat evenly and heated too strongly in one place. This can lead to problems with assembly, because the material does not expand evenly. Moreover, it can become too hot, which can cause damage to the bearings, especially with plastic kooilagers.
Disassemble the old crankshaft:
- First remove all other parts of the engine, except for the final delay.
- Loosen the carter bolts with which the carter halves are held together.
- Place a nut on the varied part of the crankshaft. Tighten the nut so far that you do not damage the thread.
- Give a few targeted taps with a large plastic hammer. The crankshaft now comes from one carter half, but is still in the other part.
- Repeat the process with the nut on the other side. Place the small crankcase on two blocks of wood, so that you can tap the crankshaft right. It is possible that the bearings remain in the carter halves. Tap them out with the help of a round bus.
- Also remove the old seals from the block.
- Thoroughly clean both carter halves and make sure that the fitting surfaces are clean.
Assembling the new crankshaft:
- Place a cloth between the vice and hang the crankshaft with the cheeks in the vice. Carefully tighten the vice so that the crankshaft cannot shoot out of the vice.
- Grease the crankshaft with some oil. Push the bearing on it as far as possible and carefully tap it with a clean bus. Make sure the bus is clean to prevent the bearing from being damaged immediately. Repeat this process on the other side of the crankshaft. Make sure the entire crankshaft is well greased with 2-stroke oil.
- Place the large crankcase on two blocks of wood, with the transmission side down. Heat the bearing scale with the hair dryer until it is well warm. This can take a while. To determine whether the bearing scale has reached the ideal temperature, keep your hand a piece of the bearing scale and