help please

[pigeonbasher1]

i need to replace the main spring in my bsa mercury, BUT i cant get the back off (the section that houses the trigger unit) ive soaked it in wd40 had heat applied had it in a vice but cant get it to budge, any ideas please, thanks in advance, pb1

[ggggr]

i need to replace the main spring in my bsa mercury, BUT i cant get the back off (the section that houses the trigger unit) ive soaked it in wd40 had heat applied had it in a vice but cant get it to budge, any ideas please, thanks in advance, pb1

This has come up a few times on here. Usually it is a case of grip the cylinder in a padded vice and put a bar through the hole in the trigger block and then hit it. Some people say to grip the cylinder and hit the block with a plastic mallet. I like Vic Thompson's idea (although not tried it yet) of putting the trigger block in the jaws of a vice and then wrapping rubber roung the cylinder and using a torniquet to undo it.
No doubt somebody will be along soon to tell you to just grip the cylinder with one hand and hte block with the other and undo it.
Slightly off thread, found that older Mk1 and mk2 Airsporters tend to have blocks that are not as tight as later versions. I put this down as using a bit of brute force to line up hte block rather than adjusting it. I guess that they were on piece work in the factory??