Tuning My FX Impact Mk1 Regulator Update (replaced FX with a HUMA) and Thank You all

I seem to have my regulator issues fixed so I thought Id send a message of thank you to all who helped. I finally replaced my original FX regulator with the correct HUMA Gen 2, 16mm piston with 16 washers. Upon close examination, upon removing my FX regulator, I found slivers of O-ring and the piston had started to disintegrate. Im sorry I can't post pictures but my new iPhone saves pictures in .HEIC and Im not sure how to convert it to something that will work on this forum. Also, I did not have to replace the 9 x 1.5 O-ring that lives in the regulator housing. I shot about one tin of pellets last night after re-tuning my .25 to around 900 fps. I used bits and pieces from Meathead Marksman, Don at AOA and of course Earnest R. to do the tune. My gun is now shooting the JSB 25 grain at 900 fps and Im getting 80 shots per fill.

my last shot string this morning was 16 shots, 896 fps ave. and standard deviation of 2.8 with a spread of 9.

Now for some reason, when I dial down the power wheel from Max to Min, I only get a reduction of about 13 fps. I guess Ill have to figure this out because I need the low power settings for shooting rats at close range, Don't need 900 fps to dispatch them.



Thanks to: Saltlake58, biohazardman, Keyman62421, Revoman, Bigragu, 2L8 (thanks for mailing me the two o-rings), 8thman, Cranky1, mobileman, kball, Teep, icycrosshairs
 
What biohazardman said. I had the same problem and it was the hammer spring. To get the power to shoot the 34 grains, I'd set the reg at 145 bar (150 max on gen 1's) and maxed out the hammer spring. After I added a Power Plenum, was able to set the reg down to 110 and back the hammer spring way back. Got my adjustments back at the same time. Play with that hammer spring first. Glad to hear this is working out.