Hello Sue,
You donn.t have to dismantle anything to look at the bevel gear, take the top off the machine and you will see the cream nylon gear, turn the balance wheel towards you and look at the gear and see if there are any broken teeth, did you get the timing instructions from me? if you did not then type my email address as you say it not as you see it and let me know how you get on
Ken
kendourof at yahoo dot com
June 2011