Adjusting Valves On a TRX400ex

So you have a pretty good understanding on how to maintnence your 400ex with the oil, and air cleaner, thing like that.  In my experience the most bewitching p
 art to the normal rider is valve adjustment.
  Usually out of concern these bikes end up at the dealership because of uncertainty of how to accomplish this service.  As a man of means you can avoid the dealership expenses and with the aid of a few common hand tools you can use that money for gas, oil and refreshments for your next ride.  Heres how to do it.

First off remove the following:

• Seat/rear fender assembly
• Fuel tank side plastic covers
• Fuel tank
• Airbox snorkel tube
• Plastic cover over top of engine
• Optional take off top engine mount and spacers

With these off it should expose the top of the engine.  From there will be four large caps which a large socket will unthread them off.  Take care doing this with the right size socket because they are a little stubborn sometimes.  Those off will expose the tappets. 

From there direct your attention the left side to the motor.  On the side of the engine will be a larger cap on center of the crankshaft, and a smaller cap above it. Remove them both. 

Next fit a 17mm socket on the bolt that was behind the
  large hole.  With a ratchet or whatever. Rotate the engine over COUNTER CLOCKWISE only.  While doing this look at the intake tappets. They will move up and down according to which stroke you are on.  For the valve inspection you will want to make sure you are on "top dead center compressios".  To know you are on the right stroke at the right place, while rotating the engine over counterclockwise.  The intake tappets will begin to go down. When they begin to go up start looking into that small flywheel inspection hole that you uncapped.   You will come aross two marks on the flywheel that are close to each other unmarked. Those are the advance marks. At that point you are close but not there yet.  Rotate slowly and you come up on a mark with F just a tiny bit further you will find and mark the T mark with the notch in that inspection cap hole
 .  If you go past that T mark just continue rotating the crank over counterclockwise until you find it right. 
At that point you will need to find a feel gauge set.  Specifically feel gauge sizes   .004in.  and .005 inches.  You can start with adjusting the intake valves.  Fit the
  .004 in feeler gauge between tappet A and Follower  B as shown in the picture.

If you cannot fit the feeler gauge in between them, the valve is too tight.  Or if it has no problem at all sliding into place, loosen the tappet nut.  Then turn the tappet screw out or in until the feeler gauge has a tension like you are dragging it across a strong magnet.  Do this too tight and the valve will be out of spec too tight.  Too loose and it will give you engine a nice little ticking noise.  When a good magnetic drag fit with the feeler gauge is acheived tighten the locking nut.  To check your work do the following.  You should not be able to easily slide in a .006in feeler gauge.  And you should be able to easily slide in a .002in feeler gauge.  If you can do that you are within factory spec. Do that for b
 oth intake side valves.  Next you will do the exhaust valves the same way.  Except the Values are different.  You will begin using the .005 feeler gauge to adjust to.  To check your work  a .007in feeler gauge should not fit easily and a .003 should fit very easily.
And thats It!!!! Your ready to reassemble the bike and go back to riding.