Air Wrench Repair?

[Worty]

Hi folks, hope you're all ok.

Bought myself a s/h air wrench (Bergen/USPro) but it's crap.  Any ideas how to fix it or increase the power.  I've stripped it down, cleaned and oiled everything and am working it from a small compressor (8 Bar/117psi) which I'm told should be enough.  I got a full refund from the vendor on Ebay (really decent bloke, said I could keep it and get it working or bin it).  The vanes look a bit worn, but everything else checks out.  The vendor said he'd been using it with a biggish workshop compressor so may need more pressure??

[RDfella]

Pressure not so much an issue (though I'd prefer around 150) as volume. How many CFM does your compressor supply, and what does the tool require? And what size bore are your hoses? 5/16"? 3/8" is preferable.

[Worty]

Cheers RD.  CFM is around 6-7, tool requires about 5.  Hose is 5/16 I think, will have to check.  Have read somewhere that turning the regulator down can build CFM value??