Unboxing a Yong Heng Compressor

What does it look on the inside of the blue cover the wiring under connected to the switch? Silent squirrel could use a picture of that wiring who posted need help.

Good choice BTW don't forget to follow instructions and oil.

Nice!!! Make sure you use some good oil in that thing. I would run it for a few mins to break it without letting it build pressure, while cooling with water of course. Some people say change the oil after the first 30 mins.. some people don't, really up to you. Just keep an eye out for the oil sight glass and see if it changes color/you see metal particles floating around.



Royal Purple is one of the best oils to use in it, they sell it on amazon for 20 a quart.

In case the owners manual hasn't been updated, please do not use petroleum based motor oil or #46 hydraulic fluid as lubricants in an attempt to save money. Get a full synthetic compressor oil of at least ISO 100 viscosity. The dollars you save on cheap substitutes only make the air stink when you run the compressor. Most important is that improper lubes shorten the life of the compressor. Most of the damaged piston ring issues and clogged check valve failures are caused by carbon deposits left by cheap lubricants. These small compressors create lots of heat internally. It wouldn't make sense to run kerosene in a new motorcycle to save money. The compressor costs hundreds of dollars. PCP's cost even more. Protect it with quality oil. Google ISO 100 synthetic non detergent compressor oil. There are many good ones.

Get a decent oil/water separator (filter)! The little one that comes with the YH is NOT SUFFICIENT to remove enough moisture to prevent it from getting into your tank or gun. Keep a couple plastic milk bottles filled with water in your freezer & put them in your water bucket when running YH. Keep a fan blowing on the YH too when running. Heat IS NOT your friend. Be patient & baby that sucker as much as you can. Also, open the moisture purge for a second or two every 5 minutes or so while filling. Just a few helpful tips I picked up & try to pass on.

What does it look on the inside of the blue cover the wiring under connected to the switch? Silent squirrel could use a picture of that wiring who posted need help.

Good choice BTW don't forget to follow instructions and oil.

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I pulled the cover off mine and posted a pic of the switch wiring on his thread.

Nice!!! Make sure you use some good oil in that thing. I would run it for a few mins to break it without letting it build pressure, while cooling with water of course. Some people say change the oil after the first 30 mins.. some people don't, really up to you. Just keep an eye out for the oil sight glass and see if it changes color/you see metal particles floating around.



Royal Purple is one of the best oils to use in it, they sell it on amazon for 20 a quart.

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I ordered Royal Purple today. It's an amazon Prime product and should be here tomorrow.

I also have one of the Tuxin filters incoming. Will probably order another and run them in series.

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Good man!

If you are just filling your gun then shorten that moisture purge interval to about twenty seconds. Maybe it is the constant high 75-85% humidity here but you won't believe how much moisture spews out of that short second and a half quick purge after only twenty seconds of compression. Otherwise it goes down the hose, and through the filter. You gotta' be there monitoring the gauge anyway, why not vent some of that moisture? I second the oil: pay now or pay later.

Down the rabbit hole I go!
My new Yong Heng compressor arrived today, even though I don't have a PCP airgun. My first one, a used Hatsan BT65 QE should arrive early next week.

A convenient and reliable source of power for the rifle is what has kept me away from PCPs until now, but frustration with break barrel springers pushed me over the edge.

I took some pics of the unboxing and thought others on the edge of ordering a Yong Heng might find the pics helpful.

Click to expand...

Yes to all of the break it in, purge often, use quality oil, get an extra filter... but holy crap, didn't anybody else notice his mailbox / package cubby??? What a thing of beauty! I am impressed!

I have two YH compressors bought the second as a backup for the first as I fergot to turn on the coolant pump several times and overheated it until it smoked. I added a switched outlet to the system so it turns the pump on before the compressor will power up to keep me from doing that from now on. The second one, my back up unit, died in about two months bad QC from the factory. Cost me a $12 part and an hour to repair it. The #1 unit that I was worried about just kept on filling my guns and tanks till I got #2 repaired and retired it.

I do not fill past 4200psi as when I do, all too often, I blow a burst disc.

Keep them cool, the oil topped off and don't fill past their spec which I think is 4350psi, I think a little less is better than the max, and the Yong Heng should last for years unless you get a bad one.

The "simple version" least expensive does not have a water separator you need one.

The "auto stop" version shuts off near 3000psi.

So you likely want the "Hardcover" or 'Set pressure' versions.

The temperature sensor only measures head temperature so running it much over 20-30 minutes can overheat the motor and other parts even if ice is used in the coolant. Ice, or a container of it, in the coolant is a good idea especially if you do not use the full five gallons of water as suggested in the manual.

Keep your water supply level with the compressor to be kind to the pump and assure a good supply of coolant goes through the compressor.

Keep your moisture filters, guns and tanks being filled above the compressor to help keep moisture out of them.

Purge the system of moisture for a couple of seconds every five minutes.

Change out your small YH filter every twenty minutes and set the old one out to dry and use it later.

Add a better filter to be sure more moisture is removed from the system. Many of us use this Tuxing three media filter although, if you feel the need, you can change media types at any time.

https://www.aliexpress.com/item/32891898253.html?spm=2114.search0302.3.35.73bf3038lshooY&ws_ab_test=searchweb0_0,searchweb201602_0,searchweb201603_0,ppcSwitch_0&algo_pvid=9120ea5e-b995-4108-83de-00688c656dce&algo_expid=9120ea5e-b995-4108-83de-00688c656dce-5

Bleed the pressure before you turn the unit off and let it run a few seconds to get the better part of the moisture out of the system. I have found that I blow less burst discs as well if I do this religiously.

Let the coolant pump run for a few minutes after shutdown to cool things off.

Down the rabbit hole I go!
My new Yong Heng compressor arrived today, even though I don't have a PCP airgun. My first one, a used Hatsan BT65 QE should arrive early next week.

A convenient and reliable source of power for the rifle is what has kept me away from PCPs until now, but frustration with break barrel springers pushed me over the edge.

I took some pics of the unboxing and thought others on the edge of ordering a Yong Heng might find the pics helpful.

Click to expand...

Yes to all of the break it in, purge often, use quality oil, get an extra filter... but holy crap, didn't anybody else notice his mailbox / package cubby??? What a thing of beauty! I am impressed!

Click to expand...

LOL me too! That was my first thought. Second was how do you keep the rain out, and whether some kind of plastic curtain could help there. But that is a beautiful wall and a great place to keep a package off the ground and relatively safe. Very classy looking.

I bought one and liked it so much I bought a second one. The first one lasted 67 hrs till failing to pressurize past 3000. The second one crapped out after about 6 hours. Now the 4-6 week wait for piston rings.

I don't know if it's luck of the draw or change in manufacturing practice but I have the auto-shutoff version and it shuts off at 4000 psi. Mine is a more recent manufacture date so it's possible they were getting complaints or requests to raise the shutoff point.

I don't know if it's luck of the draw or change in manufacturing practice but I have the auto-shutoff version and it shuts off at 4000 psi. Mine is a more recent manufacture date so it's possible they were getting complaints or requests to raise the shutoff point.

Click to expand...

The auto shut off has always been set at 300 bar. They usually shut off a little before that because of the width of the gauge needle. The sensor is at the 300 bar mark on the dial and the needle trips the off switch as it passes over the sensor. The claim that the auto-stop version stops at 3000 psi is misinformation. If you want your pump to stop manually, just disconnect the wire that runs from the gauge to the loom. I usually run mine to just over 4500 psi and after it cools it drops to about 4100 depending on the ambient temperature.