Parts that should be replaced:
1 x O ring 18mm x 1.5mm
1 x oil seal 47mm dia x 30mm internal dia x 7mm deep
1. Remove the tank and seat.
2. Remove the cam belt cover and the cover below this, after removing the
three allens on the lower cover you may need to give the cover a tap with a
rubber mallet to break the grip between the rubber seal and the crankcases.
3.Look at the bottom left side of the engine and you will see an allen bolt
which is larger than the rest (this is the crank locking point) remove this
bolt but take note that some oil will escape (I would imagine about ½ pint
but am not sure as I did an oil and filter change at the same time). [1]
4. You now need to set the engine to TDC on the compression stroke. To do
this remove the spark plug and nudge the motor round until the timing mark
on the crank pulley is almost at the top the mark on the cam pulley should
also be nearing its top position (this indicated that you are on the
compression stroke) at this point look into the hole left when you removed
the large allen and nudge the motor round until you can see a small shiny
notch in the crank (this is the locking point). Screw an M8 bolt into the
locking hole and tighten against the crank locking point, this only needs to
be nipped up. To check that you have done this correctly take a straight
edge and check that the crank pulley centre, crank pulley mark, cam pulley
centre and cam pulley mark line up.
5. Loosen the cam pulley centre bolt and remove.
6. Loosen the cam belt tension adjuster and remove (pulley on right hand
side as you are looking at it).
7. Remove the cam belt noting which way it was on i.e. direction of travel.
The belt must be re-fitted with the same direction of travel.
8. Remove the cam pulley (be sure to
put a washer or similar between the centre bolt of the puller and the end of
the cam).
9. Remove the circlip.
10. Remove the oil seal and discard. Oil will leak out unless you are able
to lean the bike slightly away from you if now about an egg cup full will
ooze out to be soaked up with a rag.
11. Remove the shim that sits against the bearing face.
12. The cam is now ready for removal. You DO NOT NEED TO REMOVE THE ROCKER’S
13. Remove the two allen bolts that sit each side of the cam you need to
remove these so that item 15 will work
14. Put the cam pulley back on, just on the edge of the splines will do and
do the centre bolt up but do not pull the pulley further onto the cam
15. slide a flat bar behind one side of the cam pulley and screw an M8 bolt
into the cam pulley just enough to hold the bar in place, repeat this for
the other side (flat bar is there to protect the surfaces of the head, I
used the alloy C spanners supplied by CCM to adjust the rear pre-load)
evenly screw in the 2 M8 bolts this will extract the cam and outer roller
bearing.
16.That’s it cam is out. Remove the thin spacer, the wide spacer, the O ring
and the bearing from the cam.
17.Slide the new cam into the head making sure that the timing mark on the
end of the cam is uppermost
18.With the cam in the head slide the bearing over cam until resistance is
felt, take a large socket and drive the bearing home the sound will change
as it seats. IMPORTANT the socket used to drive the bearing home should ONLY
CONTACT THE OUTER RACE of the bearing and UNDER NO CIRCUMSTANCES must the
bearing be driven home by the inner race or the ball bearings.
19.Slide the O ring back on the cam right up to the inner race of the
bearing.
20.Re-fit the shim.
21.Smear a thin film of oil over the outside of the new oil seal and using
the same large socket gently drive it home.
22.Re-fit the circlip
23.Slide the large spacer over the end of the cam and up to the bearing
(look at the spacer before replacing - the inner chamfered edge goes on
first this is allow space for the o ring).
24.Slide on the narrow spacer.
25.Re-fit the allen bolts to each side of the cam as removed in item 13.
26.Re-fit the cam pulley ensuring that the marks on the cam and pulley are
aligned. Do not replace the centre bolt at this point.
27.Re-fit the cam belt and the tensioning pulley. To re-time the bike keep
the left side of the belt tensioned and check the pulleys and lines are
aligned as in item 4. The teeth on the belt are quite large and it is
difficult to get the timing wrong but for my peace of mind I usually try one
tooth each side of the correct timing this looks so wrong that you know when
It’s right if you see what I mean???
28.Re-tension the cam belt using the eccentric cam belt pulley. The correct
tension is 5mm deflection measured at the left hand cam pulley. (looking at
the bike using your left hand push the belt towards the back of the bike
just above the left hand pulley the belt should deflect by 5mm)
29.Tighten the cam belt adjusting pulley nut.
30.Re-fit the cam pulley centre bolt. It is essential that you use Loctite
or similar on this bolt.
31.Remove the crank locking bolt and replace the large allen
32.Rotate the motor and re-check the cam belt tension.
33.Re-fit the covers.
34.Check the tappet clearances. You will find that these are exactly the
same as before you started! Now that says something for the quality of these
engines.
35.Check the oil level and top up as necessary.
36.Re-fit the spark plug, tank and seat fire up and enjoy.
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