Valve adjustment info
submitted by Walt ZRXOA #255.
I'm gonna' assume you have a manual. If you don't buy one before you try this. We'll follow that and I'll give you some tips.
- Drain coolant into a clean pan, then put into a plastic jug and seal up. You'll use it again.
- Remove valve cover carefully. The spark plug tube gaskets are prone to stick to the cover and can go down the timing chain gallery.
If this happens not to worry, we'll get it later.
- Remove timing cover. Have a catch pan under the bike when you do because oil is gonna' run out. The cover gasket will be stuck to
the case. You will probably have to replace it, so buy one before you start. Carefully clean any gasket compound or stuck gasket off the
cover and case. These parts are aluminum and sharp tools will gouge it. Now fish any spark plug tube gasket that may have fallen from
behind the timing plate.
- Using a wrench and turning the nut on the timing plate at the end of the crankshaft counterclockwise, align the mark "T4" on the
timing plate with the mark on the crankcase. Cylinder #1 or #4 is now at TDC. It's the one with 4 cam lobes sticking up!! You'll check
1/2 the valves at a time, then rotate the crankshaft 360 degrees to catch the other 1/2.
- Draw a picture on a piece of paper approximating that in the manual showing the cylinders and valves to check with #1 at TDC and #4
- Buy a set of automotive feeler gauges with US and metric measure. A 3" long set is fine.
- At this point, the engine must be stone cold to get good results. Measure and record the clearance between the valve shim and rocker
arm for all the valves and write the millimeter clearance on your picture.
- Remove each valve shim and write it's size on the picture by the clearance. A pencil magnet works great to remove these. The rocker
arms are spring loaded horizontally, so just slide them over and out of the way. When the shim is removed, let them snap back into place
temporarily. You'll find most of the shims have a size marked on them, but some will be unreadable. Measure these with a micrometer or
calipers and record the size.
- Using the service manual and the chart therein, select the shim size needed. The explanation on how to use the chart is very good in
the manual and once you've done a couple it will seem easy!
- Write the shim size needed next to each valve on the picture. You'll probably be able to move some of the shim you have to the
locations you need that size, so purchase of a new shim for every tight valve is not usually necessary.
- Buy any shims you need from your dealer, or if you have plenty of time, order them from a discount parts dealer. I'm told they can
be had for about $4 each this way. You dealer will want $10 - $11 each, unless you can swap the shims you have for what you need, plus
some $$. I did this and got the 7 shims I needed for about $32. Call first. Some dealers only do this if you have them do the
- Carefully install the new shims and check the clearance to verify in tolerance. If you did everything right, it will be. If you drop
any shims, and you will, use the pencil magnet to retrieve them.
- When all are in spec, slide each rocker arm over and coat the shim and rocker arm contact points with a small amount of "moly"
grease. This will cost about $2 at the auto parts and you'll have enough to do this 50,000 times!
- Put it back together. Do the valve cover first, so if anything get dropped into the chain gallery it's easily retrieved. Be sure to
use an automotive silicone sealer at the places indicated on the valve cover gasket. Here's a money saving tip. Secure your new timing
cover gasket to the cover with gasket cement. I use Permatex #2 non-hardening. Put a very thin coat of the moly grease on the other side
which contacts the case. Put silicone where indicated on the case. And install the cover. In this manner, your timing cover gasket will
be reusable. Note that 2 of the bolts of the timing cover, indicated in the manual at 10:00 and 11:00, go into oil passages, so the
threads must be coated with a thread locking compound/sealer. Pick the non-hardening kind from the auto parts.
- Put all the hoses on TIGHT, let them sit overnight and retighten, then fill up with coolant and bleed the cooling system.
- Check the oil and add if needed. Now you're good to go.
- Hope this helps. It'll seem easy once you get into it.