[EDNY]

Had this grinder for a while and decided to use it on my trailer deck replacement today...absolutely worthless...no power at all. 

100lbs air at hose and oiled it.......

Need to dig out my receipt


http://www.eastwood.com/4-in-air-cut-off-tool-w-forward-and-reverse.html

[Rattiac]

Probably looses its torque through the extension.
Kinda like an extension on a impact.
There's little tricks you can do to improve airflow on fittings and couplers.

[EDNY]

I have several air tools and grinders...this one is gutless

[sammons]

Ed, I've never had one but i'll bet Rattiac is right on.  Most of those bigger high rpm grinders/polishers go thru mass quantities of air quick. I have an Ingersoll-Rand 4,900rpm 7" variable speed pull trigger air polisher/grinder that at 125psi pressure on an 80 gal tank that runs for 3mins till it bogs down. .  So I just use a 5" wire brush on it.

[EDNY]

Ed, I've never had one but i'll bet Rattiac is right on.  Most of those bigger high rpm grinders/polishers go thru mass quantities of air quick. I have an Ingersoll-Rand 4,900rpm 7" variable speed pull trigger air polisher/grinder that at 125psi pressure on an 80 gal tank that runs for 3mins till it bogs down. .  So I just use a 5" wire brush on it.

10-4 ...even with my 80 gallon tank topped off it stops with the slightest down pressure...that's why I have (3) "electric" angle grinders