27.4 too tight and 27.2 too slack

[Bimly]

I'm with duxuk. If it goes in a couple of inches past the clamp, then it's not deformation near the clamp and my money would be on rust or crap further down the tube.

Get a bit of broom pole, evostick some 180 wet and dry round it and sand out the inside ad far as you need. Grease and hopefully Bob's your uncle.

 

[TOMAS]

This is another way to give it a good clean.... https://www.youtube.com/watch?v=xRIFqasCOSg

 

[d8mok]

Re:

That looks a decent idea. I’m away currently so I’ll try that once I’m back. However it does look already clean in there so not holding much hope.