How to adjust your valves
Adjusting the valves on the DS can be intimidating if youíve never done a shim style valve adjustment before.
Some of the tools youíll want / need are, a feeler gauge (min range .002in - .010in), A good inch pound torque wrench
with a range of about 20 inch pounds to 200 inch pounds, A good foot pound torque wrench with a range of about
5 ft lbs to 80 ft lbs, 5mm hex socket that will fit your torque wrench and a 10mm 6 or 12 point socket that will
also fit your torque wrench, A caliper for measuring OD dimensions in mm (millimeters) for the shims (I like the digital ones).
Remove the seat, front fascia plastic, the gas tank cover and gas tank. This will expose the valve cover.
Remove the valve cover to expose the top of the head.
Put the timing at TDC (Top Dead Center). To do this remove one of the spark plugs.
This makes it easier to spin the crank into position. On the right side of the motor in the center of the
magneto cover is a plastic plug with a straight blade slot in it that needs to be removed. Insert a 7mm allen
wrench into the center. Use this to rotate / spin the crank causing the piston to move into the TDC position.
Look in that hole while spinning the crank. Reach through to the right side of the motor and turn the allen wrench
inserted earlier. Carefully watching for a notch in the crank. When you see the notch in the crank, you know your at TDC
(and this is very important) make sure that the cam lobes are pointing away from each other. The exhaust cam lobe
should be pointing toward the front of the quad and the intake cam lobe should be pointing toward the back of the quad.
Insert the TDC locking bolt to hold everything in place. Part #529 035 617
Using your feeler gauge measure the valve gap by pushing the blade of the feeler gauge between the shim and cam
lobe and record the gap. You want the thickest blade possible to be able go between the shim and the cam lobe. You
should be able to feel some resistance. If you CAN NOT fit a .006 blade then try a .005 blade and so on.
Your valve gap (valve lash) needs to be between .004in and .006in or .1mm to .15mm. The valve shims are what
needs to be changed to adjust the gap. The valve shims come in a range of 2.00mm through 3.10mm thick and are 29mm
in diameter. Every .05mm = .002in. So if you have a shim installed that is 2.45mm and the valve gap reads .010 your
gap is to wide by .004in (010 - .006 = .004). In order to get a .004 thicker shim you need .05mm x 2 = .10mm
add that to the current shim of 2.45 and you know you need a 2.55 shim for that valve lash to be corrected. You
could use a 2.60mm shim and still be OK in this case as well. Since the allowable range is .004 to .006 and youíre
now at .006 going to a 2.60mm shim would put you at .004 and that is in the allowable range.
OK now to swap out the shim / shims to the correct ones.
Loosen / remove the cam chain tensioner. This is located at the back left side of the head.
Take a piece of tie wire or equivalent and tie it to the cam chain. Then tie the other end off to the frame.
This is so that you donít lose the cam chain down into the bottom of the cam chain cavity.
Remove the cam chain guide that is located between the two cam timing gears.
Remove the upper half of the cam bridge. Loosen all the hex bolts on the cam bridge and lift it off.
Lift the cams out. And then remove the lower cam bridge to expose the shims and shim buckets.
There are many ways to remove the shims from the buckets. A blast of air, a very strong magnet, small pry
instrument etc. However I am afraid of loosing a shim down into the cam chain cavity. So I remove the entire shim
bucket (valve tappet) and then remove the shim from the bucket with needle nose pliers.
Once you have all the correct shims in place. Replace the lower cam bridge. Then starting with the exhaust
cam. That is the one with the decompression mechanism on it and the one that goes in the cam bridge closest to
the front of the quad. Put some assembly lube on the cam bridge where it cradles the cam and some on the lobes
Put it back in place with the lobes facing toward the front of the quad and so that the timing mark on the timing
gear points towards the back of the quad when you twist the timing gear clock wise as far as the cam chain will let you.
Put some assembly lube on the intake cam carrier and the intake cam itself. Install the intake cam with the cam
lobes pointing towards the back of the quad and so that the timing mark on the cam timing gear is pointing directly
at the other timing mark on the exhaust timing gear. Make sure you are turning the gear clockwise to put pressure on
the cam chain when checking the timing marks. Remove the tie wire from the cam chain.
Put the upper cam bridge back in place and hand tighten the bolts. Set your torque wrench to 89 inch pounds and
tighten the cam bridge bolts in a cris cross pattern. Re check all the valve gaps with your feeler gauge.
They should all now be between .004 and .006. Install the cam chain guide. Be sure to use blue lock tight
on the threads and tighten to 89 inch pounds also. Take another look at the timing marks and make sure they point at
the marks on the cam chain guide when you twist the cam gears clock wise. Install the cam chain tensioner and torque
it to 30 foot pounds. And check to make sure the timing marks are still lined up.
Install the valve cover and torque the valve cover bolts to 89 inch pounds.
MAKE SURE you remove the TDC locking bolt and reinstall the regular hex bolt and torque it to 18foot pounds.
Reinstall spark plug, fuel tank, tank cover, front fascia, and seat.