Adjusting the Valves FOR THE EX 500 AND NINJA 500This procedure is very simple and applies to almost any rocker arm engine. Few tools are required and they are simple ones at that.
Why: Valves are adjusted to maintain some clearance between the operating mechanism and the valve seat, to assure the valve closes on the seat for a good seal. If this fails to happen the engine will run poorly and damage could result. The amount of clearance is determined by the design of the valve train and the mfg. Experience as to wear life. Wear will usually decrease the clearance. (tighten) as the valve sinks deeper into the seat.
Generally the settings are done cold and allowance for heat expansion is included in the recommended settings. Deviating from these settings is a bad move, unless you know more than the manufacturer does (you don’t)
10 mm box wrench
Medium flat blade screwdriver
Feeler shims .005 .007 .009 two of each recommended
Procedure for EX500:
Drain the coolant (oils ok)
Remove the tank, right side coil, coolant pipes (the hoses can be left on).
Note: the carbs can be left on but it’s a lot easier if you remove them too.
Remove the cam valve cover
Remove the two copper oil lines
Remove the plugs in the left side engine cover
Remove the spark plugs (put a wad of paper towel in the cavity to prevent dropping something into the plugholes (this is a bad thing).
Using a 14mm socket wrench turn the engine over in a clockwise direction until the “C” mark on the flywheel is visible in the small inspection port and the cam lobes on the #1 cylinder face away from the rocker arms. (#1 is the right side as on the bike).
Note at this point the cam wheels will show the “IN” mark and the “EX” mark level with the cam box outboard surface (approx.)
Now to adjust the valves check with the feeler gages the space between the Adjusting screw and the top of the valve Intakes between .005-.007 Exhausts .007- .009 if they are within that range your golden (footsing around to make the perfect will gain you nothing).
The next cylinder: Rotate the crankshaft clockwise until the second piston is TDC and the cam lobes are pointing away from the valves. And check cyl#2.
If they are not: loosen the ten mm lock nuts (both) slip 2 feelers under each Screw and adjust hold the adjustment with the Screwdriver and tighten with the box wrench. This can cause the adjustment to change so check again. Using two feelers cancels any wear on the rocker arm to its shaft.
Turn the engine until the other cylinders cam lobes are pointing away from its valves and repeat steps above.
Recommended at this time to re torque the head bolts to 35 lbs.
Also remove and clean the “O” rings from the water pipes and the hole in the head they came out of. Reassemble with grease or RTV to prevent leaks
Tips: Setting the valves on the tight side will improve the engines performance and make it quieter, but shorten the inspection interval by ½