Help! I'm having a ignition problem

["Bill Miller" <millerb@netusa1.net>]

Oh knowledgeable ones,

I am having a strange problem here.  I just got through changing out the
timing gears and chain.  I'm sure they are on correctly. Fun!  I thought it
was supposed to be easy.  I've now got a very interesting new problem, maybe
I've had it all along.  Cylinders 1,2,and 3 are firing perfect.  Cylinder 4
is firing intermittently!  I can't figure this one out for the life of me.
What can cause just one cylinder to fire intermittently?

Bill