Classic Valve Angst

[brianlojeck]

It was a bad day for mag's this sunday... had my classic and my RT Pro out, and had weird issues with both.

I'm not turning up any answers in the search, so I'll go ahead (having seen "posting and you" ;-) ) and start a new thread...

my classic mag, on co2, has never really been "stable" at the chrono. it's usually +-10fps, and slight moves to the adjustment screw change the velocity pretty dramatically.

Since it's an older gun, running co2, I just figured it was the way it was.

It's gotten a lot worse though the last time.

I'd set the velocity to about 260, and by the end of the next game it wouuld be shooting 150. turn the velocity screw about 5-10 degrees, and it jumps to 325. turn it back about 5-10 degrees, and it goes down to 170. go back and forth a TINY amount, get it back to about 260, and by the end of the next game my wife is complaining again about not getting any range. check at the chrono, it's back to 150ish.

I just replaced ALL the o-rings a few months ago, I keep it WELL lubed, and I haven't cracked the valve open recently (after reading Unka Phill's note to replace the reg seat after every opening of the valve).

The co2 tank is full, and I tried it with another tank to the same result. The tank is vertical, so liquid shouldn't be a serious problem, and she doesn't shoot a lot, so chilling the tank isn't an issue.

it's got a brand-spanking new regulator piston (kept blowing off gas with my air tank), is time to replace the spring pack and regulator pin?

[eNder159]

that's a possibility

[BlackHalo]

Stabilizer

Put a Palmer Stabilizer on there and set it to about 600-650 psi.

One reason that HPA is so consistent is that it's a double regulated system. Double regulate CO2 (Stabilizer and then the Classic AIR valve) and see what happens .

[brianlojeck]

Put a Palmer Stabilizer on there and set it to about 600-650 psi.

One reason that HPA is so consistent is that it's a double regulated system. Double regulate CO2 (Stabilizer and then the Classic AIR valve) and see what happens .

that would be a good thing to do, but if I didn't _need_ a stabilizer last year, I shouldn't need a stabilizer now.

My mag is sick, I'm not sure a stab would help it at this point.

[BlackHalo]

Oh

Whoops, for some reason I thought this was an ongoing situation.

Cphil said to change the reg seat every time you open the valve? I open mine up all the time to check for dirt and I haven't replaced it in over 2 years. Mind posting a link to it?


Ok so let's eliminate the obvious -

Try it with an HPA tank to see if it's erattic then. If it's not erattic then there's something up with your CO2 tank. Who knows, maybe something is constricting the flow?

Might want to check the orientation of the reg seat. Make sure it's the right side up.

Check the condition of the reg pin, might have gotten damaged somehow.

The spring pack isn't supposed to be a wear item (mine is over 10 years old) so I kind of doubt it. But hey, give it a shot if you've got one around.

Maybe the aduster is backing out?

Other than that, I'm stumped. There isn't much else that will affect velocity like that, anyone else have any ideas?
Hope this helps.

[brianlojeck]

>Whoops, for some reason I thought this was an ongoing situation.

well, it kind of is, but not nearly this bad. the gun was usable til this weekend.

>Cphil said to change the reg seat every time you open the valve? I open mine up all the >time to check for dirt and I haven't replaced it in over 2 years. Mind posting a link to it?

hmm... my search-fu is not strong, can't find it. He basically said that the pin makes an indentation in the seat, and that opening the valve without replacing the seat can cause problems because you'll then have two indentations.

it wasn't a "must" thing, but a "I'd suggest" thing.


>Try it with an HPA tank to see if it's erattic then. If it's not erattic then there's something >up with your CO2 tank. Who knows, maybe something is constricting the flow?

haven't tried it with HPA recently, but I did try it with two co2 tanks. Also, would a bad tank make the velocity adjustment unusually sensitive? (5-10 degrees between 150 and 325 is not normal I hope)

>Might want to check the orientation of the reg seat. Make sure it's the right side up.

it is. I also believe these work correctly if you flip them over (wasn't that a suggested field fix in the old classic manual?)

>Check the condition of the reg pin, might have gotten damaged somehow.

this is my leading candidate. right now.

>The spring pack isn't supposed to be a wear item (mine is over 10 years old) so I kind of >doubt it. But hey, give it a shot if you've got one around.

I'd be buying one, but considering my mag is pretty damn old as well (#00455) replacing it seems worth the $12 for peace of mind.

>Maybe the aduster is backing out?[/INDENT]

my sharpie mark says no.

Thanks for the advice. it's only about $40 for pin, spring, parts kit, I may just take it apart, clean it all out real good, and replace as much as I can, then see what happens...

[BlackHalo]

Idea

if you have an extra regulator try this -

1) Remove the reg seat, pin, and the little spring behind the pin.
2) Put the valve back together without these parts and you've basically gutted the AIR reg.
3) Hook up the extra reg and set it to about 400-450 psi.
4)See if it's erratic. If it is, then it's not the AIR reg.

I did this with 2 Stabilizers and CO2 and it was pretty consistant, but I didn't like stabilizer hanging off the side of the AIR valve.

At this point I'm just spitballing, I'm bored at work