Submitted by Chris
The valve adjustment on a D16A1 is quite simple. All you need is patience
and a few simple tools.
It is also very important that you adjust the valves when the engine is cold, like
sitting overnight, because if the engine is warm, the parts will expand with
the heat, and the adjustment will be off.
Good luck!
You will need:
1. Remove the spark plug wires, and Remove the upper timing belt and valve
covers, there are 4 10mm crown nuts and 2 10mm bolts. Put them out of the
way for now.
2. Turn the wheels all the way to the left so that you can access the hole
for the crank pulley bolt that is in the splash guard. Put your 17mm socket
and extension through there to be able to turn the crank pulley. Turn it
only counterclockwise, that's the way that Honda motors spin. Turn until you
reach Top Dead Center for piston #1, indicated by the notch on the crank
pulley lining up with the indicator. You do this to make sure that the cams
are not pushing the valves down, as that will also effect the adjustment.
3. Now go back up top and start with whatever side you wish. I usually do the
intake valves first. Get out your feeler gauge (you know which one because
you have a helms, right? ;-), i use .005 intake and .006 ex), Insert the
feeler gauge between the cam surface and the rocker arm. Feel how much the
feeler drags between the two surfaces...there should be moderate drag...not
to heavy but enough that you can feel it. If it's too loose or tight, you
need to adjust it.
4. Loosed the locking nut with your 12mm wrench. With the feeler gauge still
in place and the wrench still on the nut, use your flathead screwdriver to
turn the adjusting screw until it makes light contact with the feeler gauge.
Feel with the gauge how much drag there is. When there is light-moderate
drage on it, hold the screwdriver firmly in place and tighten the locking nut
down again. Now recheck the clearance to make sure it is ok. Try using
feeler gauges that are one size smaller and larger than your target to see if
it is adjusted correctly.
5. Repeat on the other 3 valves
6. Now you have to do the cylenders in the firing order becaue it involves
the least amount of turning. The firing order is 1-3-4-2. Turn the motor
until you see that # 3 is at TDC, shown by the fact that both cams are not
pushing down on the valves....when you see it you'll understand what I am
talking about. Now adjust these valves and repeat all the way through all 4
cylenders.
7. Now go through with your wrench and make sure that all the locknuts are
tight...
8. Put the valve and timing belt covers back on and tighten the nuts to 7 lb
ft.
9. Remove the 17mm socket from the crank pulley before you start the motor,
if you don't it will spin with the motor and fly off (ask me how I know :-P)
10. Put back your plug wires and start it up...