Tuning Impact MK1 reg creep

[bowdude]

Need some insight on this thing. I resealed the gun not to long ago & have been fighting a slow leak, 50-75bar over a week. Well today I got it out & tried once again to find the leak but came up with nothing again. Got it back together & was gonna shoot it but the regulator is creeping pretty good. Reg set around 110bar, was shooting to get it sighted in at 30yrds. I was fighting it a little bit to get it zeroed, shoot 2 rounds adjust scope. Get it banging zero, let it sit for about 5 minutes shoot, it’s off by 1/2” low. Shoot again it back on zero, grab the chrony, if you shoot it fairly quickly it’s hole in hole but if you wait about a minute it’s 1/2” low. Chrony shows a 35-40fps increase if you wait about 1 minute. Looked at reg & it’s creeping roughly 15-20bar. Anything to do for the regulator creep & anything I should be look directly at as for a slow leak?? 

 

[Vetmx]

Just replace your reg piston and you’ll be “banging zeros” again in no time.

 

[jking]

You might just replace the the O-rings that are probably worn and set and see if that wont do it. That's what I just did to my Impact a few days ago and it's working like a champ now. Maybe a whole dollars worth if you have them already. If not holler at me, I think I have some spares. 

Jking

 

[nervoustrig]

Creep is caused by surface imperfections in the valve seat. You can dress the surfaces with a sequence of ever finer wet/dry sandpaper, or perhaps just replace the piston as Vetmx said. I know no mechanism by which the O-rings can cause it.

Also, the fact it’s shooting faster after a rest indicates there is too much hammer spring tension. Once you get the issue addressed, dial it back to about 95 - 97% of the maximum to optimize the ES (make it less sensitive to minor pressure variations).

 

[Eddy1840]

I just replaced the o’rings on the adjustment screw also Installed a new piston and polish the washers 

now it’s working like a champ

 

[bowdude]

Thanks I’ll take a look at the reg tomorrow. Is there a certain direction to washers go in the reg?? 

 

[Vetmx]

Yes, there is an arrangement. Don’t mess it up.

 

[2L8]

Don't forget the O-ring in the breach for the reg.

 

[Keyman62421]

Count them. They are cupped and spooned in a certain order. Take picture!

 

[bowdude]

Count them. They are cupped and spooned in a certain order. Take picture!

Well a picture is out since I’ve had it apart twice & didn’t think to take a picture but I could a thread talking about fx regulators & should them like this ()()()()(). I’m gonna get it apart again later.