TS1 Mikuni Flange Adaptor Problems

[Tabby]

I have been running in my TS1 fitted with a LTH inlet manifold, and a Mikuni flange rubber with the following moulded into the rubber M-VM36-200, after 150 trouble free miles (nothing altered / changed) the carb popped off 3 times on my short journey to work today.
At work I refitted the carb, and cable tied it on to stop it coming off again & managed to limp home using very little throttle.
When I removed the flange the rubber part seems very soft and quite slack when the carb is pushed on, it seems like the rubber has swelled....has anybody else had this issue, or have any ideas to stop the next one I get going the same way.
The carb does not hit the foot board as I have cut it to allow more movement, and its not hitting the side panel, or the tank.......surely a rubber should last longer than 150 miles!!
The only thing I did notice was the jubillee clip is the thin type so I will be fitting a wider one.

[smiffy]

Same thing happened to mine, was touching the toolbox so i thought that was causing it till it came off with no toolbox in as well.
Turns out i was tightening it too much and starting to force carb out of rubber which i agree is very soft but mine was like that from new
and ive now done about 1000 miles with it. I made sure carb, and manifold were completly clean and dry then refitted.
Since ive been more carefull fitting it it hasnt come off. Yet.
(Dont want to be doing it in the rain on the A34 with no hard shoulder again!)
Hope this helps.