I set the tdc according to the clymer and the tech page. the decomp solenoid was at the correct distance. That is one part of my question as the solenoid was only measureable in one position of tdc and  at 180 off from that position it would not extend. I am assuming that was correct. The next problem is no matter which way tdc the rocker arms have no play. I am assuming that the valves are to tight. I need help. Any suggestions? I previously posted this in the wrong section.

To do this you have to wrap your mind around the 4 stroke engine cycle...it is Intake, Compression, Power, Exhaust, but since we are looking for the compression stroke, I'll explain it from TDC at that position at 3:00.

There are 2 top dead center positions but the one that you want is on the compression stroke.  It might be hard to visualize crank rotation, a piston going up and down, a horizontal paint mark, camshaft rotation, and a clock running backwards...but what the heck, I've got coffee.

Remove the spark plug.  Remove the timing plug on the left alternator cover.  Get a 17 mm socket and a breaker bar, if you have one.  It gives better control.  Now turn the engine counter-clockwise only to position the paint mark on the rotor bolt with the groove on the engine case at the 3:00 position.

To find the compression stroke, watch the valves operate as you turn the engine.  When you approach TDC in the compression stroke (going from 9:00 to 3:00) both sets of valves will be closed...in fact, the valves remain closed through a full 360 degrees of crank rotation, but what you can't see is that the camshaft is turning during this time too....and we want the lowest position on both cam lobes.

If you pass the 3:00 position do not reverse the rotation, but go around 2 more times while watching the valves again.  But watch the valves...

...From TDC of the compression stroke at 3:00, both sets will be closed as the piston goes down to...

...BDC in the power stroke at 9:00, then the exhaust valves open as the piston goes up to...

...TDC in the exhaust stroke at 3:00, then the intake valves open as the piston goes down to...

...BDC in the intake stroke at 9:00, and now both sets are closed as the piston goes up to...

...TDC in the compression stroke at 3:00.  Stop.

Both sets are now closed, the piston is at TDC, and whether you feel rocker movement or not, you are ready for the real fun

to be cont:

gregs' methiod needs to go into yhe yech section..even i undersood it!!

justin_o_guy2 wrote on 01/13/08 at 11:45:14:


I mentioned not reversing the crankshaft above, but anyway...

First of all, you don't reverse it because you might be putting (theoretically) slack in the cam chain which means the cam might not be in the correct position relative to the crankshaft.  Remember that you are turning that fun little do-da on the other side too.  As well, you are turning the cam lobes in the opposite direction against the rocker arms too.

Second, you are seeking the smallest diameter portion on the cam lobe, and that position is directly opposite the full lobe height of the cam.  There is a gradual increase in cam profile from one point to the other, and since we don't know exactly how much, go for the lowest point which is at the 3:00 position.

Third, do it like the manual says to do it.  They have a lot more engineers than we do

Good answers, thanks guys.

Thanks Greg, your explanation enabled me to get it right. This was my first try. Thanks again to all

justin_o_guy2 wrote on 01/13/08 at 13:51:07:

Justin,

I don't think that being slightly off the mark on the timing marks will make much difference as far as the valve clearance is concerned.  The camshaft diameter is probably pretty much the same whether you are +/- a few degrees on the crankshaft...considering that the crankshaft rotates at a ratio of 2:1 with the camshaft.  

So, 1.0 degree on the crankshaft would only be 0.5 degrees rotation on the camshaft anyway.  It's just my habit to only quote the exact specs and never use the words like "close" when discussing an engine setting.  After all, what I call "close" might mean "in the ball park" to someone else.  Know what I mean?

Besides, just how accurate is the paint mark?  Could there be a small amount of error in it?  Which direction is the error?

BTW - If I ever find a good set of v-blocks, I might have to check the camshaft profile with an indicator.  Just to see how much is "close".

From my CD, here is the paint mark...



Now if you really want to get accurate, you could always remove the alternator cover