DR400 Valve adjustment
Tools required: A metric socket set and a few spanners, allen keys or allen sockets, a torque wrench (low torque under 25ft/lb), breaker bar / T bar, clean engine oil, a few shims (or order when apart and knowing what you need, meaning you will have to leave it disassembled for a day or two), feeler gauges, magnet, digital camera, and RUM.
Note. You can pre purchase a shim kit, I sometimes see them for sale off flea bay, or a good bike shop can order one in for you
Time required: First time this may take you a couple of hours of quality shed time. After you’ve done it a few times, simple valve checks take about ½ hour or less.
– Clean your bike, having a clean bike is easier to work on and prevents dirt from falling into the engine.
– Jack up the bike. Having the bike level makes it easier to work on, plus oil won’t drain out when you unscrew the side cap. Of course you could use the rear tire to turn over the engine.
– Remove the seat, radiator shrouds, and fuel tank.
– Remove the spark plug.
– Disconnect the two breather hoses and route them out of the way.
– Remove the three bolts on the valve cover. Don’t loose the rubber gaskets.
– Carefully remove the valve cover- taking care not to ruin the head cover gasket.
– Remove the caps on left side of the engine crank cover
– T bar, not a ratcheting type, rotate the engine to TDC. You can also use the rear wheel and one of the higher gears to turn over the engine. A line with a T should be visible and the cam lobes should be pointed away from each other as shown. If not rotate the crank another 360 degrees.
http://www.youtube.com/watch?v=BH-KFrpwo3w
– Use a feeler gauge to check the clearance between the cam and bucket on the two intake valves. Clearance should be 0.10mm-0.20mm. The feeler gauge should have a slight drag when inserting/removing on the correct measurement.
– Use a feeler gauge to check the clearance between the cam and the bucket on the exhaust valves. Clearance should be 0.20mm-0.30mm. The feeler gauge should have a slight drag when inserting/removing on the correct measurement
– If the clearances are in spec, you are ready reassemble. If not, write down your clearances (not a bad idea anyway), and double check that the Engine is at TDC. Take note of the cam position, especially the markings on the sprockets in relation to the crankcase. A digital camera is especially helpful here.
– Now remove the cam chain tensioner. If you are using an automatic cam chain tensioner (stock), you can remove the main bolt first.
http://www.youtube.com/watch?v=wtiUCCIxTJQ
– With the cam chain tensioner removed, now it’s time to remove the cam (the one with out of spec valves.) If you need to adjust both intake and exhaust valves, do them one cam at a time so you don’t drop the cam chain into the engine. Remove the corresponding cam holder and cam, note: you will also have to remove the cam guide as well. There are two small dowels on each holder, don’t let them fall into the engine.
http://www.youtube.com/watch?v=JSmYDeqi27s
– Finally remove the bucket and shim using a magnet. Usually the shim will stick to the bucket, make sure not to drop it into the engine.
– Measure the shim and workout the shim size you need to use. Then use the following formula to calculate the new shim size. New Shim Size=Measured Clearance – Desired Clearance + Existing Shim Size Make sure all of your calculations are in the same unit (in or mm). Put the new shim on top of the valve and reinstall the bucket.
http://www.youtube.com/watch?v=nOiNYKa8ayY
Now cover the cam journals and faces with assembly lube or motor oil. And one at a time install the cams. Check to make sure the piston is at TDC and install the cams so that the indicators are at the 9, 12 , and 3 o’clock positions. NOTE: You will have to put a finger into the CCT hole to take out any chain slack. Failure to do so could result in the cams being in the incorrect position.
http://www.youtube.com/watch?v=1LrLT9edX6o
– The intake sprocket indicators will be at the 12, 3, and 6 o’clock positions as shown.
– Now install the camshaft holders and top guide (using the two longer screws on it.) and tighten the bolts to 10 N/m (7ft/lb) in a crisscross pattern.
– Next reinstall your cam chain tensioner. On an automatic cam chain tensioner, reset the automatic tensioner as shown, mounting the tensioner spring, bolt and washer last.
http://www.youtube.com/watch?v=_23aTM2TeWg
http://www.youtube.com/watch?v=ZNqyMxpadmU
http://www.youtube.com/watch?v=bgZirsbaEh0
http://www.youtube.com/watch?v=9iodhz8_m-E
– Now turn the engine over a few of times slowly to check to make sure that no piston/valve contact occurs. The engine should turn over smoothly, without binding. If your exhaust cam has an auto decomp you will hear a click right after TDC, so don’t let that alarm you. Check valve clearances again. If correct proceed, otherwise check your maths and remove the shims and try again.
– Reinstall the valve cover, putting a small amount of high temp salastic on the half moon rubber pieces. Torque the three head cover bolts to 7ft/lbs initially and then to 10 ft/lbs. Or if you can’t get a torque wrench in there, torque the bolts until they are snug.
– Then reinstall the spark plug and torque to 8ft/lbs.
– Refit the breather lines and reconnect and fit the horn.
– Replace the timing plugs, and reinstall the tank, seat and shrouds.
– Start and test run happy days
http://www.youtube.com/watch?v=guwVkEAZMx4
TB
