mch6 compressor questions

[aviator8]

Hi,
I see this guy up for sale in my area. It is an older model and comes with the gas and electric motors. There is only this one picture and not having a history with scuba compressors I wanted to ask the resident experts.

What should I be looking out for in a sale like this on an older Coultri? Other than hours, and obvious issues what questions would you recommend I get clarified? Does this thing look serviceable or should i just walk away?

 

[SurfLung]

I have virtually the same compressor in the gas version. They were made in the 1980's. This is what it looked like when I picked it up. Bought it for $250 last summer. AND I had the same question as you: "How do I know if its any good?"

Most people ask the seller to run it to prove it works. But with something old like this, it may have been sitting unused for several years. The gas engine probably won't run without servicing. And with the 4th stage cylinder being below the oil sump, you want to be careful not to damage it with hydraulic force. So my plan was pretty simple. I planned to just check and see if the compressor and engine rotated freely. I slowly pulled the starter cord thru a few revolutions with the drain and fill valves open. Nothing seemed broken or froze up so I paid the man and brought it home.

I have a post here with video and brief description of my restoration:
Vintage Aerotecnica Coltri MCH-6

 

[aviator8]

Wow 250, that sounds like a great deal. This guy is asking 600. BF had me spending more than I wanted so I am going to hold out. If he still has it in 3-4 months and has dropped the price I may take a drive out to him.

 

[SurfLung]

My seller was asking $500. I phrased my offer this way, "Would you take $250 if I pay cash and just pick it up directly with no packing or shipping?" I was blown away when he said yes.