- Details
- Category: MAC Service Guide (1965)
- Hits: 5486
The Kickstart
Dismantling Kickstart Ratchet and Spring. (Fig. 15.)
Drain the oil from the gearbox by removing the plug from the end cover (Fig. 16). Take out the three bolts holding the kickstart bearing to the end cover and draw it out of position with the ratchet, and kickstart crank, etc. Preserve the layshaft thrust washer from inside the ratchet.
Should the spring be broken the kickstart crank cotter may be removed at once, but if not the bearing and ratchet have to be held against the tension of the spring whilst driving out the cotter.
Remove the cotter nut and washer. Obtain two 2-in nails of small enough diameter to enter the breather holes in the ratchet. Knock these into the bench 1 19/32 -in. (1.593-in.) apart, or into a piece of wood held in the vice. Cut off the heads leaving about ½-in protruding from the surface of the wood.
Place the kick-start assembly, with the ratchet teeth downwards over the nails, entering the nails into the breather holes. Turn the kickstart bearing in a clockwise direction against the spring sufficiently to allow the head of the cotter to clear the disengaging ramp on the bearing. Drive out the cotter and gradually release the bearing.
If the spring is broken the ratchet will pull out of the bearing when the crank is tapped off. If unbroken tap the ratchet through far enough to expose the loop of the spring where this is fitted to the ratchet. Unhook the spring from its mounting and pull the ratchet out.
Note that the ratchet carries three thrust pins, 3/16-in dia. x 9/16-in long (.187-in. x .5625-in.) which must be preserved for refitting. These must not be confused with the three clutch thrust pins which are much shorter,
Take out the engaging spring which will be loose inside the kickstart bearing. Unscrew the kickstart spring anchor peg and remove the return spring - or the part of it if broken.
Replacement of Kick-start Spring. (Fig. 15.)
Push the end of the spring with the smaller loop (X) into the mouth of the kickstart bearing and by twisting the spring clockwise whilst holding the bearing firmly it will be found possible to work round the spring coil by coil and get it into place. In its free state the outside diameter of the spring is greater than the internal diameter of the kickstart bearing, but by twisting it round as described the coils will be compressed and will enter easily.
Leave the end of the spring with the larger loop, and one coil protruding, and manoeuvre the smaller loop in the kickstart bearing under the hole which carries the anchor peg and screw the peg home with its tip (X) through the spring loop.
Fit the three thrust pins into the ratchet. There are six holes, but the three which act as breather holes are slightly smaller than the others. Note specially that the correct thrust pins must be used. These are 3/16-in x 9/16-in. and are the same part as the big-end rollers. Discarded big-end rollers may be used as replacements. Do not, however, confuse them with the clutch thrust pins which are only .453-in. long. Stick them in place with a little grease.
Fit the engaging spring over the ratchet and push the ratchet into the kickstart bearing, engaging the loop of the spring (that was left protruding) over the anchor lug, that is formed on the ratchet.
Twist the ratchet round clockwise and push it further into the bearing at the same time entering the spring.
Place the ratchet over the two nails that were used in dismantling and fit the kickstart crank over the end of the ratchet.
Turn the housing round clockwise just far enough to allow the cotter to go through the crank across the flat on the ratchet. It fits from front to back. Do not in any circumstances turn the housing further than is needed to fit the cotter. Any extra tensioning of the spring will permanently distort and damage it.
Refitting Kickstart Assembly. (Fig. 15.)
Before fitting the assembly to the gearbox see that the layshaft washer is in place against the ratchet gear, the kickstarter bearing bush on the end of the layshaft, and the kickstart layshaft thrust washer in the ratchet.
Do not use a gasket between the face of the kickstart bearing and the gearbox end cover. Tighten the three bolts fully. Refill the gearbox.