Air-cooled engine anti-ring rubbers

[BlackIP2]

Is there any guidance on what the correct fitting is of the anti-ring rubbers on air-cooled IP2/Classic engines?
My IP2 is up on the bench and I can now clearly see three untidy rows of rubbers on the right rotor housing cooling fins, but none on the left hand housing. Both end plates look OK, with the rubbers spaced evenly down the corners of all the fins.
There is no mention of the rubbers in the factory workshop manual, presumably as they were never intended to be removed?
Thinking back to my old two stroke days, the idea was to evenly space rubbers on unsupported cooling fins to prevent ringing.
The cooling fins on the IP2 look to be well supported anyway, but I can see no reason why only the right hand rotor housing has the rubbers and I suspect someone has played about with them in the past. I can't say I've noticed any ringing when the engine is running.
Any views on this please?

Fin details.jpg

[johnbirchjar]

Hi,my Classic has the rubbers on both sides of the engine,but over the sixty odd thousand miles that the bike has traveled, quite a few of them have shrunk/perished and fallen out smily
I havn't noticed any "ringing"either,probably'cos rotories don't vibrate (unlike the Two Strokes of old)J.B.

[Richard Negus]

When new, the rubbers are relatively soft and are hammered into place using a flat tool shaped like an open-ended spanner.
They harden with age and engine heat, lose their elasticity, and often fall out of their own accord.
It was a mind-numbing job to fit 400 of them, making sure they were in line with their neighbors or Mr Rowley would grumble.
R.

[BlackIP2]

I was trying to clean up the fins and levered the rubbers out - they came out easily. They are indeed all hard but I've tried to put them back in some form of neat pattern which is a nightmare as they have a mind of their own! But I won't worry too much about them now.
Cheers

[johnbirchjar]

400 ,I wonder how many are still remaining in my old girl now,I seem to have been picking them up from the garage floor on and off for years ,J.B.

[BlackIP2]

I think the 400 Richard referred to is the number of air-cooled engines fitted with the rubbers, ie, 300 IP2s and 100 Classics.