Used coltri mch6 portable infos!

[miker-gr]

I have read many threads about this compressor! And i must say i am confused a little!
Some people state that is very good for it's price and other consider it as rubbish!
I have found one from 1996! I don't have access to it so i can't say about it's condition right now!
The owner says it's in perfect condition! How can i check this? Was there a problem with this model?
Thank you!

 

[michael-fisch]

You get what you pay for!
20 years ago I spent the extra $ to buy a Bauer new, and have never regretted my decision.
I hope, in 20 years, that you are as happy with your MCH6 - but if not, your experience won't be that much different than that of many others who bought MCH6's and expected them to last for years.

Michael

 

[Sbiriguda]

Do this portable compressor really work? Sorry for my naive question, but if they are cheap and easily transportable, and they work fine, I would expect them to replace the bigger and more expensive ones, provided many diving centers are also in places not easy to access...Moreover, the price for filling the tanks, especially in the Maldives and other similar destinations, is so high it would make them very competitive. There must be something I am missing, or otherwise they are not really comparable in terms of quality

 

[SurfLung]

You Will Love the MCH6
- I recently bought this older Aerotecnica Coltri MCH-6 and it runs as good as a new one. Here's a picture of my MCH-6:

- I also have 3 diving buddies who each have the MCH-6 in MaxAir 35 branding. They all love their MCH-6s and have had zero problems with them in 3-4 years of heavy use. These guys each dive 40-100 dives a year and fill some of their friends tanks as well as theirs. I recently bought a used Aerotecnica Coltri MCH-6 after my friends showed me how their MaxAir MCH-6 machines function. Mine is quite a bit older than theirs but it works the same and as well as a new machine:
- Here are the advantages I see to the MCH-6:
1. Proven 4-Stage pump. Four stages give a better compression ratio than 3 stage pumps. This means it runs cooler than a three stage for the same amount of work. I say "proven" because I think this is the same four stage pump they've been making since the even older days when it was called the Olmeva 6000.
2. Actual Free Air Delivery CFM... Meaning the fill rate cubic feet per minute is rated from 0 psi to full, not "SCFM" which is 500 psi to full.
3. Easy maintenance: It's easy to open the filter tube and pop up the filter cartridge to check the blue test strip. It's easy to check the oil and top it off or change it.
- Personal experience... My little Aerotecnica is probably similar to the "EU" version of the Compact MCH-6. I bought it used. It had been in storage awhile but turned over fine. The motor started with a prime of fuel in the spark plug hole but wasn't getting fuel to keep running. I took apart the gas tank and carburetor, cleaned corrosion and gunk from the gas tank, cleaned the filter screens. But it still wouldn't suck up the fuel and keep running. Then I put new, TIGHTLY Clamped hose clamps on the vent tube. One pull on the cord and she was running perfectly. I filled a Scuba tank from 0 psi to full at a rate of 2.93 cfm. The current EU model specs say it runs 3.2 cfm... Mines running just as good or close enough!

 

[rcontrera]

The 1996 model has JIC tubing fitting so when it comes time to do service, you will have to change out the cooling tubes to the standard compression fitting style. Also, it is important to have the seller run it to make sure that it comes up in pressure. If it had been run hard and put away wet, the 4th stage is in the sump and prolonged sitting (a few months or longer) will allow any moisture in the sump to collect on the piston causing rust to the cylinder, piston and valve. Not a huge chunk of money but an additional cost all the same.

You will find that people that have no problems with the MCH6 are those that actually use them all the time. "Motion is Lotion" so use it regularly.

 

[cathal]

My 2c - I have my electric MCH6 since 2011. I think it’s a 2008 mode. It fills nitrox, I run helium through it, it fills my 100 liter air bank (at 70 min runtime at a time)and it is easy to transport. It has never let me down.
The only change I have made is to wire a tachometer into the switch to more accurately measure runtime for changing the filter and oil.

 

[SurfLung]

The only issue I've had with my USED MCH-6 is not the MCH-6... Its the gas engine. Crud in the gas tank and carburetor has given me hard starting and no starting. I've been cleaning it up and when it gets fuel it runs like a champ. The latest test fill was running at almost exactly 3.5 cfm from 0 psi to full. Turns out it is a very common engine with lots of YouTube clips on re-building the carburetor, etc. I've got the gas tank cleaned to bare metal. So, no more crud, rust flakes, or bad gas. It needs new gaskets and diaphragm and probably some more carb cleaner. So I need to get that taken care of. But the MCH-6 compressor itself seems to be in great shape.

 

[michael-fisch]

Gasoline that isn't used for a few months seldom remains a homogenious mix thats why you should buy it use it and then drain the tank.
Ever thought what the 10 is, in E10 Gas? I do know that my small Honda gas engine for the compressor hated it, after it had been sitting in the tank after 6 months.

Michael

 

[SurfLung]

Gasoline that isn't used for a few months seldom remains a homogenious mix thats why you should buy it use it and then drain the tank.
Ever thought what the 10 is, in E10 Gas? I do know that my small Honda gas engine for the compressor hated it, after it had been sitting in the tank after 6 months.

Michael

I agree! I used to use Stabil additive in the gas when storing my boat, lawn mower, and other small engines over winter. My son put me on to using airplane gas in my small engines. And, I haven't had a gas problem since. Airplane gas is as pure as it gets and has no ethanol to turn into varnish after a few months. In fact, it is designed to keep its integrity through years of storage.

 

[KentB]

I’ve had mine for just over 2 years and have zero complaints.

It’s electric for what it’s worth.