Originally Posted By charlestkirby
Its actually quite a complex problem...

+1
the top surface of the filler neck doesn't have a nice broad flat surface to give a decent seal and as Charles says is inclined to cut whatever gasket material you put against it.
I still think that short of welding on a better neck, GLLOQ's aluminium plug with an o-ring seal is the best arrangement.

Calum
M3W Vol1
Vol2