As I'm about to sell my machines , I've been checking everything, prior to advertising and been shocked at the poor standard of work within my main machine, which is probably the best known portable around.
There missing bolts and loose nuts throughout and a substantiol gap where the secondary vacuum was mated to the casing
When the machine was re assembled and tested, there was a very noticable increase in power.
I'd always been happy with the performance but there were occasions, over the past couple of years, when the extra power would have been useful.
rob m