matching motor rpm with pump - compressor squealing

by Brett Brown
(Mustang, OK)

I bought an 80 gal husky compressor off craigslist. The seller said that the compressor had fallen over and broke the pump, so he replaced with a Harbor Freight pump.

the thing squeals like crazy (most of the time) and once i noticed it smoking off one of the pump heads.

I've tried belt dressing without luck.

Wondering if the motor is turning the pump too fast. Motor says 3450 rpm while the HF pump says 1140 rpm. I expect the pulleys are reducing the rpm to the pump shaft but wonder if I should buy a smaller pulley for the motor. Any advice appreciated.
Can post pics or model #s if that helps.
Thanks.
Brett

__________________
Bill says...

Hi Brett. If the pump says that it needs xx RPM and you are driving it faster than that... why, exactly?

As far as I'm concerned, the first thing is to get it working at the correct speed.

Yes, adjust the sheave size so that the 3450 RPM on the motor is reduced to the correct RPM of the pump.

I think that if the sheave on the motor is 6" in diameter and turning at 3450 RPM, then if you put a 2" sheave on the pump shaft, that should rotate the pump sheave at 1150 RPM. I think. Someone please double check and comment ! :-)

Then, lets see what happens to your compressor symptoms. Also, make sure it's lubricated properly.

Cheers,

Bill