well got my tank filled with yong heng air compressor but???

Mine does the same thing. Probably 4250. That's enough. I was thinking of replacing the gauge with an adjustable pressure one but I decided to keep the 40 odd bucks that the new gauge would have set me back. If you must fill to 4500, just do what airgunfans suggests and disconnect the wire that runs from the gauge to the motor. It sounds like you have been trying to restart it after it cuts out. If you try to start the motor while there is pressure in the line, you will kill the motor in no time.
 
4500 would be nice, but most all compressors out there, will start to bitch after 4000. My Yong Heng does better than my Carette. Carette did ok For the first 6 or 7 fills, then it got to where after reaching 4000/4100, it would take another 30/45 minutes to reach 4500. I'd like to have that extra bit of air, but it ain't worth the strain on the compressor. Anybody have a compressor that goes to 4500 with NO problems? What kind, link please.
 
4500 would be nice, but most all compressors out there, will start to bitch after 4000. My Yong Heng does better than my Carette. Carette did ok For the first 6 or 7 fills, then it got to where after reaching 4000/4100, it would take another 30/45 minutes to reach 4500. I'd like to have that extra bit of air, but it ain't worth the strain on the compressor. Anybody have a compressor that goes to 4500 with NO problems? What kind, link please.

One word - Shoebox

http://www.shoeboxcompressor.com/
 
To you all who say that your compressor complains at 4000+ psi, then there is definately something wrong with your compressor. I have been using mine for 6 months now and the noise doesn't change right up to 4500 and I do mine manually and watch it like a hawk. I run it for 20 minute intervals and change the oil every 5 hours. Seriously, it should never struggle. Just a YH I bought on ebay.
 
My YH has no problem in getting to 4500 psi but I only fill my rifle directly so the time for the compressor to work under that pressure is rather short. Not any sign of struggling observed. In fact I have the feeling that it can easily go higher but I haven't tried it. it's a genuine YH and full-feature model with auto shut off and dual water "cyclone" separator. I brought it directly from the factory in China. 
 
4500 would be nice, but most all compressors out there, will start to bitch after 4000. My Yong Heng does better than my Carette. Carette did ok For the first 6 or 7 fills, then it got to where after reaching 4000/4100, it would take another 30/45 minutes to reach 4500. I'd like to have that extra bit of air, but it ain't worth the strain on the compressor. Anybody have a compressor that goes to 4500 with NO problems? What kind, link please.

My Carette tops off a 3 liter tank from 3k to 4.5K each time without any difficulty. From what you are describing it appears that you have a leak in your system, most likely in a hose or connector. The sound of the compressor does change pitch slightly when the pressure exceeds 4K psi but in no way does mine sound labored.
 
My burst discs let go at 4200, so can't go higher anyway. I think they are aluminum, but could be stainless....they measure .009" thick. I was thinking about punching some out from .012" aluminum shim stock that I have.......maybe not.... would need to make a punch first. 4200 is enough pressure for what I need now, although some guns I like hold/need more pressure.
 
I want a compressor but I refuse to be a Beta tester again or get a dud. If cash we're on trees, Bauer Jr. Gas operated. Until then.

I also would be happy w/a 6K rented cylinder. I live near Prax Air, another huge gas company & welding shops. I know I'd need a good regulator but it seems this area is afraid of being sued by a dead morons family or Federally 6K tanks are frowned upon as, well, you know. I can't even find a firestation where the chief will allow tank fills of current hydro tested WITH a donation. WTH is going on? I read oh I bring the guys doughnuts & coffee & they always fill my tank. The dive shop owner has lost his mind. I bought 20 4500 fills for $180.00 got about 7 free from a cool employee. Owner says, who sold you that card as 4500psi fills are $12.00, not $7.00 each. I said your wife sold it to me. Oh, she must of made a mistake. Wait a minute. They fill 0 to 3K for $7, but only 2500ps worthi from 2K to.4500psi for more. I'll be buying a gas compressor one day. Until then, pump & a tank but not shooting as much as if air were free or something crazy like that. Free air. LOL. 
 
I have the simple Davv su30 compressor. $212 (with an ebay coupon) shipped from Shanghai in 5 days. Runs flawless so far. I ran it for 15 to 20 mins with full synth IR full duty compressor oil under no load and changed out the oil. No metal or dirt so that was a pleasant surprise. I dont have a tank and just fill guns direct but would have no concern about using this to top off a tank. I am switch over to Royal Purple on the next oil change.
 
the auto shut off, auto shut off at about 4100 psi. do i need to replace something for it to work again?

it filled my 9l tank from empty in about 5 different sessions.

If you have the adjustable auto shutoff knob/pointer on the gauge, just turn it up a little more. Those adjustable shutoff gauges are not all that accurate. Mine shuts off about 200psi lower than whatever mark the red pointer is set to. If I want 4500psi, I set it to 4700psi.