DISASSEMBLY & ASSEMBLY
With the cylinders, pistons, and other outer parts removed, the crankcase is split as follows:
- Remove the oil strainer, oil pressure switch, and crankcase nuts.
- Keep the cam followers of the right crankcase half in position by using the retaining springs.
- Use a rubber hammer to break the seal between the crankcase halves. Under no circumstances insert sharp tools, wedges, etc. between the crankcase halves, for this will lead to damage of the engine case mounting surfaces, which will cause oil leakage when reassembled.
- After the seal between the mating surfaces has been broken, remove the righthand crankcase half, the crankshaft oil seal and camshaft end plug, and lift out the camshaft and the crankshaft.
- Remove the camshaft followers, bearing shells and oil pressure relief valve.
Assembly is generally the reverse of the foregoing procedure, but includes the following:
- Before reassembling the crankcase, check it for damage and cracks after thorough cleaning. Mating and sealing surfaces should be cleaned especially well. A solvent should be used to remove traces of the old sealant from mating surfaces.
- Flush and blow out all ducts and oil passages.
- Check the oil suction pipe for leaks.
- Check the studs for tightness. If the tapped holes are worn, correction involves the installation of Helicoil inserts.
- Insert the camshaft followers after checking both the followers and their bores in the crankcase.
- Install crankshaft bearing dowel pins and bearing shells for the crankshaft and camshaft.
- Install the crankshaft and camshaft after the bearings have been well lubricated. (When installing the crankshaft, note the position of the timing marks on the timing gears.)
- Install the camshaft end plug, using a sealing compound.
- Install the thrust washers and the crankshaft oil seal. The oil seal must rest squarely on the bottom of its recess in the crankcase.
- Check and install the oil pressure switch.
- Spread a thin film of sealing compound on the crankcase joining faces. Use care so that no sealing compound enters the oil passages of the crankshaft or the camshaft bearings.
- Keep the camshaft followers of the right crankcase half in place by using retaining springs.
- Join the crankcase halves and evenly tighten the fasteners to the torque specified in the Engine Torque Specifications Chart.
First tighten the 8mm nut which is beside the 12mm stud of the No. 1 crankshaft bearing. Only then should the 12mm nuts be tightened fully.
- Turn the crankshaft to check for ease of movement, and check the end-play of the crankshaft. The crankshaft end-play is measured with the engine assembled and the flywheel installed.