After listening to what I thought was certainly the timing gear typical racket I first substituted temporarily the fuel pump with an electrical but the clatter (noise) persisted I pulled the grill, rad, timing gear cover and both crank and cam gears. Nothing appears excessively loose between the gear(s) or on either drive or driven 'keys' There is a ridge however worn into the brass or copper cam retainer which seems odd - there were no spacer shims as I see a comment in the manual about clearance - and thoughts. The noise is at low speed and seems to subside then above 2000 rpm or when the oil is cold ... any thoughts, thks Greg

Greg;

You are already into the motor from the sound of it, but maybe you can still get something out of this compilation of my Timing Gear Notes: http://www.sw-em.com/Timing%20Gear%20Notes.htm

Good Hunting!

I had a similar situation on my 122. Turned out to be a noisy water-pump.

A failing timing gear will make a clacking noise for a long time before the fiber gear separates from the steel hub. You will likely not feel any play. You may see oil stain streaks emanating from the hub out across the face of the fiber gear--a sure sign of separation.
There absolutely has to be a a steel spacer ring behind the timing gear. You need that--and a new brass or steel cam retainer plate. -- Dave