Hi 8lueoval,
Well Frosty won the Championship over the weekend didn't he and you're a Ford man ?
Anyway regarding your issue, there are two parts that play a major role.
The first one is how much cork is in the primary clutch as I fear there may be none left and if that's the case you have a metal to metal situation and that will create a bang as its a cone (wedge) scenario which is one of the most major grip and bonding situation. The cork would act as a dampener to this gripping action.
The other thing I wanted to ask you is there any reel and bed knife contact at all if you rotate the reel by hand while the machine is not running (of course)?
Both these situations will work against each other, so can you inform me regarding the contact issue before we go any further ? also I note that primary Land Roll chain is grossly out of adjustment which indicated there has been quite a lack of maintenance done on this machine by it's previous tenant.
BTW. Can you furnish us with a close up photo of the bed knife and reel contact area. Lay the machine back onto its handles grips and ensure the sun is shining into this area and then snap away.
Cheers,
BB