Manual - Chapter 1 Engine

3. Dismantling the engine unit: general

  1. The engine unit is so designed that the only parts of it which cannot be removed easily while the main crankcase/cylinder block casting is in the frame are the auxiliary drive shaft, including the starter idler shaft and starter clutch, and the output/balancer shaft assemblies. If the bellhousing or the crankcase lower section are to be removed to reach any of these components, the gearbox and final drive must be removed first (see Chapter 3 - Gearbox) so that the clutch can be withdrawn (see Chapter 2 - Clutch) to give access to the bellhousing. The engine and frame will require very careful supporting if this procedure is adopted. See Section 7.
  2. All other components can be removed with the main crankcase/cylinder block casting and the bellhousing still in the frame. Usually, components can be easily removed leaving others intact. For example, to remove the crankshaft it is possible merely to drain the coolant, to remove the engine left-hand, right-hand and front engine covers and to disconnect the cam chain before removing the big-end and main bearing caps and withdrawing the crankshaft.
  3. K75 model owners should note, however, that it is necessary on reassembly to align timing marks on the crankshaft and balancer shaft gears. Since these marks may not be easily visible from the crankshaft opening it is recommended that this task be undertaken only with the engine unit removed. The amount of preliminary dismantling necessary to remove the balancer shaft with the engine in the frame means that there is in practice very little extra work to remove the entire unit and gain much improved working conditions.
  4. Owners of all models should note that if a major overhaul is to be undertaken, or if more than one component requires attention at anytime, the engine unit should be removed from the frame. This is a basically simple procedure which permits excellent access to all components and allows the major casting's to be cleaned so that the high standards required for successful rebuilding are maintained.
  5. While notes on alternative procedures are provided where necessary, this Chapter is based on the assumption that the engine/transmission unit is to be removed from the frame, that the engine will be separated from the clutch and transmission and that it will be completely overhauled.