Step 1
To gain access to the valve gear, remove
the rocker box screws and remove the
boxes, being careful not to tear the
gaskets.
Step 2
Remove
the rocker arm pivot screw. You must be
careful here because you definitely do
not want to strip the slot in the screw
head. It takes a proper fitting straight
screwdriver. In figure 1 you can see
that there is a spacer on one side of
the rocker arm. Remember where it goes.
Also, you will need to keep all the
valve parts for intake and exhaust
separate in small Ziploc bags or
similar. You should always put them back
on the valve where they came from.
Remove the push rods by pushing the
rubber grommets that seal the pushrod
tubes at the head down the pushrod
tubes. Now you can remove the push rod
tubes.
Step 4
Now
we are ready to remove the cam box. It's
held in place with four cap head screws.
Remove these screws and lift the cam box
free of the engine. Again, do it slowly
and be careful of the gasket. Once off,
turn it upside down and remove the cam
followers noting which one is for the
exhaust and which is intake. If you spin
the cam inside the cam box you should be
able to see the timing mark. Look for a
little dot. If you refer to figure 2 it
will help you ID the timing mark shown
as 'A' in the drawing. Now is a very
good time to inspect the cam lobes.
Replace the cam if it looks worn. To
remove the cam you will have to remove
the cam pivot shaft by loosening a tiny
set screw on top the cam box and tap the
pivot shaft out with a 1/16 drill bit.
Step 5
Now
for the tough part. You need to make
yourself a little tool to locate the cam
while you reinstall it. This tool takes
the guesswork out of timing the Saito. I
used the shank of a 2mm drill bit
inserted into a small length (about
25mm) of 4mm O.D. copper pipe.
Now that you have made yourself this
little tool you are ready to put the cam
box back on the engine. Turn the
crankshaft so that the piston is at TDC
and turn the cam so the timing mark is
pointing straight down like figure 2,
then insert the tool in one of the cam
follower bores and you will feel the 2mm
shank drop into and lock the camshaft.
Now simply drop the box back on the
crankshaft. Cool. You did it. Now bolt
it down. Careful not to over tighten.
Re-assemble in the reverse order and
reset valve clearance to factory
tolerances.
