Maintenance Evol regulator adjustment, with access tool

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Here is a re-post from Tom on adjusting the regulator on the original Evol.

Regulator - The baseline of 2000 psi can be simply set by gently turning the adjuster until stops on the seat and then back out 7/8 of a turn. The adjustment is very fine, approx. 1 hour per 50 psi. Clockwise decreases and counter-clockwise increases the reg pressure. We will set them at tad higher at the factory for a couple of reasons. A slightly higher pressure will allow for frictional velocity losses of pellet weight slugs by a simple striker adjustment. Also, we have found the shot count to be slightly higher (36 regged shots with 44 gn. JSB) and the ES slightly tighter. As you can see from the independent ES data published in this thread; ES is not an issue.

As a general philosophy, EVOL is designed to have a wide operating range in terms of accuracy and velocity. The extremely stiff barrel system allows for this wide velocity range by mitigating harmonics, thus reducing the need to micromanage fps. Of course there is always a sweet spot; EVOL is designed to have a very wide sweet spot.
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Some thoughts on what I have experienced having two different Evol's with different barrel lengths, plenum extensions, and regulators... My older original Evol has the purple regulator with the 42cc plenum extension installed an 18" barrel, and rather extensive modifications to the air flow capabilities from it's stock form. My newer Evol has the blue regulator with a 27cc plenum extension installed and a 15" barrel and has only had minimal work done to the valve, valve body and transfer port.

When it comes to adjusting the different regulator's for optimal air flow, PFE, and low ES within the system, each individual's barrel length seems to have played the biggest factor in where the regulator pressure was set at because of waisted air exiting the barrel. The short barrel liked a lower 1900 psi regulator pressure to keep a tight extreme spread and light hammer strike. When that was set up at 2250 the hammer spring adjustment could not calm the extreme spread to what the Evol is capable of. At 1900 it produced nearly the same power (75-80 PFE) as when set higher too; again, limited by barrel length. The longer 18" barreled Evol likes the regulator at a higher 2400 psi to keep the ES tight and produces higher power with a quick blast of air (98-100 PFE).
 
The single best improvement to the rifles is the external adjuster! Seriously if you like to tinker and tune quite a bit, break down and buy this upgrade. It really makes the gun so much better and much easier to tune. The fact that you don't have to worry about tearing out o-rings when you have to remove the caps constantly.
 
Are the parts available yet? I'm not sure why I didn't think of it either but what size is the reg adjuster? A simple hex on a 1/4" or 3/8" ratchet extension would work very easy to not need to remove the reg, just the end cap.
 
The single best improvement to the rifles is the external adjuster! Seriously if you like to tinker and tune quite a bit, break down and buy this upgrade. It really makes the gun so much better and much easier to tune. The fact that you don't have to worry about tearing out o-rings when you have to remove the caps constantly.
The back side of the shaft doubles as a spring tension adjuster, so I don't have to pull the stock off. Minimal drilling and pad removal required. @Dairyboy they are 3/16 & 5/16 hex. 🤙


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