Trx 400ex valve adjustment

Answer 1

not sure of the specs, but! ... you will need, a set of feeler guages, a straight slot screw driver, a set of metric combos, and a socket set will help. start by removing the seat, front fenders, and gas tank, your cylinder head will be visable, you should see 4 covers at the top corners of the motor, the covers are a little bigger than a silver dollar and will have a nut molded right on the cover itself. (nut on them should be 17mm) remove all of those. WATCH YOUR GASKETS! on the left side of the motor (sitting on the machine) there is a crankshaft nut cover, and a top dead center window. remove the cover ( again a straight slot) and the window cover (the dime sized one about 3 inchs above it). put a socket on the crank shaft nut and rotate counter clockwise until you see a definative notch in the tdc window. this may take you a few turns to get it stopped. if the compression of the motor is giving you troubles, remove the spark plug. when you are at exact TDC, all of you valves should be open, and you can probably wiggle a few of the rocker arms. loosen the lock nut, (8mm?) insert the feeler guage that the spec calls for between the rocker and the valve and tighten the screw down until you snug it up on the guage. you should keep it to where you can slip the guage in and out with a tad of resistance. keep the screwdriver in the screw, and tighten the lock nut back down being careful not to turn the valve adjuster. repeat, repeat, repeat... now pick up the tools you got mad and threw and your set. remember, some of the valves could have streched, so you may have to loosen the valve adjuster. remember, turn the crank with the wrench a few times and listen for any horrific noises before you start it.

Rich, 4 year Honda parts expert.

IMPROVED ANSWER......The specs for the valves are .005 for the exhaust and .004 for the intake, the exhaust valves are the 2 in the FRONT of the engine, the intake valves are the 2 facing the rear or the quad...when you are turning the crank to get it at top dead center, look in the small window on the crank case, there are multiple markings you MUST be on the correct one(the correct one is a T) NEVER TURN THE CRANK BACKWARDS IF YOU PASS IT just continure turning until it comes back around...you shouldnt have to remove the spark plug at all to do this.