Compressor problem, what is it?

[Tim240Z]

I have a 60gal Kobalt 7 HP compressor, belt drive, cast iron, oil lubricated upright.
Here is the problem: I switched it on today (it is in the shed behind the garage), but I noticed it was running kinda long.....I went around the garage into the shed to look at it.....it smelled kinda funny, but I couldn't put my finger on the smell. It was stuck at around 95psi (set to 120psi), and would not go any higher, even though it was still running. I took the air cleaner off, and noticed that there was hot air coming OUT.....that's not right!??
Is the compressor shot? Can it be rebuilt?

Thanks,
Tim

 

[Fast Orange]

It's hard to tell with the limited info you've provided,but it sounds like a problem with the check valves in the head.I am not familiar with the Kobalts,but my experience with larger industrial two stage compressors is that a leaking valve will cause what you're seeing.Carboned up or cracked valves will cause air to be blown back out of the intake filter.
Before you tear into the heads,check a couple of basic things first. Are the belts tight?Is the voltage at the motor correct-possibly a power company brown out-nominal 240 volt power can be cut by as much as 10% during high demand.I had an factory of packaging machines start doing very strange things when the 3 phase 208 volts dropped under 190 volts on a hot day due to a power company brown out.

George