impact mk2 issue need help

[Max115]

I wasn't expecting myself to be having an issue with a brand new Impact MK2 .22. Here I am, reaching out to you all for advise and possibly some solutions to my problem that I am facing now.

I got the gun less than 3 weeks ago. Due to bad weather, I haven't been shooting it much, only 3 sessions in total as of today.

It came with factory setting at 90-95 bar, Max.

I shot the 18.1 gr JSB and got 854 fps average on my first outing on Sept.14.

2nd outing Sept.16 and got 837 fps.

3rd outing Sept.21 and got 837 fps as well. Full tin of 500 pellets done.

4th outing Sept 24, I adjusted the hammer spring by 4 turns (1/4 turns each time) and velocity went up to 840 fps

4 more turns yield 860 fps

4 more turns yield 893 fps

2 more turns yield 895 fps

2 more turns yield 897 fps. I stopped and noticed the point of impact were opening up. I knew I had to up the reg pressure, but I didn't have the proper tool that day.

Today Sept.25. I turned the reg up to 100 bar and noticed the velocity was 650 fps. I then turned the reg up to 110 fps and velocity dropped to 573 fps.

Now I was surprised and dumbfounded as to what was happening to my speed. The POI was way low as expected with the decreased of velocity from 895 down to 573 fps.

The next thing I did was turned the hammer spring back 16 small turns back to original and my speed was all over the place:

406, 424, 436, 476, 487, 481, 484, 474, 479, 452, 442

I had to stop.......

My question is: Do any of you experience this or know why this had happened?

I will emailing the vendor tomorrow and ask them what I should do next. I wasn't expecting this to happen, not after paying this type of money for it to malfunction.

thank you all for any comments and advice.

Alex 

 

[Glem.Chally]

I would get a baseline and set the reg to 110 or 100 if you prefer and open the valvestop to line 3.5 or 4. Then take all the slack out of the hammer spring tensioner with it on max to where it gently stops (wheel won't want to turn) then back it off a 180*.

What do you get at this setting?

 

[Max115]

Hi Glem.Chally, thanks for chiming in.

I didn't touch the valve stop and it is open at 4 I believe. The gun was shooting fine with the factory setting at 90-95 bar at Max dial (without me adjusting the HS screw).

I only turned in the HS screw hoping to gain the velocity, which it did, by 50 fps after I did 16 (1/4") turns. I increased the Reg pressure to 100 then to 110 bar, now my velocity is in the 400s. Something is definitely not right internally. Maybe the oring inside the valve?

thanks.

Alex

 

[cfs916]

I highly doubt it’s the reg. Sounds like something is loose or out of alignment. I’d check the barrel/pellet probe first. If that doesn’t solve it watch FX master class to understand the rifle better. I’m sure it’s something simple you can fix urself. 

 

[Max115]

Thanks. I will check for anything loose but I am still puzzled with the lost of velocity.

 

[2fast2furious]

Check c3 o ring. It's in the parts diagrams. It's always goes bad and you get low fps. Replace it with a darlin or whatever its call and you will get your fps back,.sometime 30 to 40 fps more too.

 

[Diamondback]

Sounds like maybe you increased reg pressure and now your overpowering the hammer spring / valve, getting lower velocity.

By then reducing hammer spring tension you are further overpowering the hammer spring / valve with the higher reg setting, getting even lower velocity.

You then increased reg pressure again, further overpowering the hammer spring / valve yet again, getting even lower velocity.

Try reducing reg pressure again and note results.

 

[biohazardman]

All of that makes perfect sense if you understand how the gun operates. Glem and Diamondback Have it right.

Turn your reg pressure back down to factory spec or maybe +5bar. Before you do so I would remove my tank and loosen the reg gauge to release all the pressure in the gun. Some people shoot the gun down, others turn the reg screw to do the same thing. Your reg gauge should read 0 when you are turning the adjustment screw back in to approximately where it was before you made adjustments.

Turn your hammer spring adjustment screw back in to where you had it set, after your adjustments, for your most accurate groups back a bit from your maximum fps and set the dial to to 5 or Max.

Turn the valve adjuster out past the 4th ring to where 4.5 or 5 would be.

That should put you back to near 900fps once again or a little better if it doesn't the hammer may be hanging up or you have other problems.

 

[Eaglebeak]

I am guessing that your reg. gauge is dodgy, which is fairly common. The reg would have been set at around 120-125 BAR from the factory and your starting velocity sounds about right for stock settings. By raising your setting by 20 BAR your hammer is probably struggling to open the valve. I'd go back to where you started and up the reg 5 bar at a time with the HST backed a few turns back from max. If that doesn't help, you have a warranty issue.

 

[Keyman62421]

Make sure your barrel is aligned and tight. ???

 

[Max115]

hi all, thanks for the feedback. later today I will remove the bottom, turn the reg back to factory 90-95 bar. I already return the HS back to factory before. I will test to see if the velocity back to original of 840fps. If I don't get the velocity increase from 400 fps, then it is safe to say something is not right internally. I will wait for the vendor's suggestion before opening up the gun to avoid voiding the warranty.

 

[Max115]

I removed bottle, turned reg down to 95 bar and got velocity ranging from 430 - 588 FPS.

removed bottle again and turned reg down to 90 bar and got 565 - 649 FPS.

this is down to factory setting and I am still off by 200 FPS.

I didn’t adjust any HS.

any ideas? Thanks

 

[Airgun-hobbyist]

The C3 bumper (o-ring) is probably bad. They do not last too long. Change it out to a delrin washer.

 

[Max115]

That’s what the vendor told me as well to replace the C3 bumper. Where would I get the delrin bumper?

thanks

 

[biohazardman]

I removed bottle, turned reg down to 95 bar and got velocity ranging from 430 - 588 FPS.

removed bottle again and turned reg down to 90 bar and got 565 - 649 FPS.

this is down to factory setting and I am still off by 200 FPS.

I didn’t adjust any HS.

any ideas? Thanks

Did you adjust the hammer spring back up to near max? Did you turn the valve adjuster out past line 4? You may want to try that first and then it looks like your velocity is going up as you turn down the reg down you may want to turn it down more and see if velocity continues to go up. I know the new gauges are better than the old ones but yours could still be off 15-20 bar. One gauge on my Impact was off 40bar! If none of this werqs you may want to check on the C3 bumper. You don't have to tear your gun down very far to get at it if you do it right.

 

[2fast2furious]

It is not the reg or hammer. The hammer has enough force to open the valve even at 160 bar. So idk why people think.the reg is up too high and you get valve lock. I set my impact reg to 160 bar and my impact have no problem openings the valve. It's the c3 o ring. It's easy to change out. Why ship it back and wait weeks and have to pay shipping. Here is a video.by ernest on changing it out. Really simple. You just need guts to tear your impact apart.



https://youtu.be/Ru7pX-J5iSg



https://m.youtube.com/watch?v=ik7Uyj-Luh4

 

[Max115]

Thank you 2fast for the video links. I will check the C3 and see if it is damaged or not. Hopefully this will be an easy fix instead of sending it back to the dealer for warranty service.

where would I buy the delrin oring while I wait for dealer to send me the spare.

thank you all again for chiming in, greatly appreciated!

 

[cfs916]

@Max115

FX USA

 

[Glem.Chally]

If you come down to my place (burnaby) i have a piece of Delrin or maybe nylon that the OD is probably right. Just would need to open up the ID would be easy. PM me if you're interested i can take a pic when im home.

 

[Airmanator]

Do you have a compressor like a yong heng or hatsan lighting. They usually ship with the white delrin washer. I just use the one that came with my compressor. These washer are use to seal fittings no stop leaks. I have fire over 2000 pellets though my gun and havent had a problem since I replaced the c3 o ring. If you dont have the darlin, you can order from aliexpress. You get like 50 for under $5 shipped. but shipping is 3 weeks. If you cant wait fx probably have them but shipping alone is $8.

https://m.aliexpress.com/item/32874612295.html?trace=wwwdetail2mobilesitedetail&spm=a2g0s.9042311.0.0.67054c4dBCkrER

These are the one that came with my hatsan lighting.