serious reliability issues with a classic

[mountainbob84]

I tried to post this earlier but nothing happened so here goes again. I have a classic automag with serious reliability issues. I bought the gun used so I don't know what the origin of the problem is or how long it has been happening. the gun fires consistantly, aside from a very slow first shot and a relatively rapid drop in velocity for no apparent reason (the gun will be shooting fine and then within the course of ten shots start dinking balls)which I'm sure are related to what ever is causing the other problem which is that the gun completely stops firing, of course this always this always happens at the beginning of a fire fight so I think the rapid firing might be a trigger. The trigger just goes slack and won't come tight again. Not sure what is going on with this. sometimes this is accompinied by a hissing of gas similar to the sound made when the trigger is held down. the only way I'v found to get the marker to work again is to depressurize the gun and then recharge the gun. when the gun recharges the trigger tensions again 90% of the time. sometimes I can make the gunbegin operating again with a hard whack from the butt of my hand to the back of the velocity adjuster but not consistantly. cylinder pressure seems to have no bearing on the occurance, it is just as common with a fresh tank as with a near empty one. I oil my gun constantly. Before every time I play I usually put 2-3 drops of a very lightweight oil into the asa, this is often repeated 1 or 2 other times throughout the day. my complete setup reads as follows: standard feed automag classic, stock bolt, stock trigger frame w/double trigger shoe, Boss progressive and Big-shot barrels used interchangeably depending on paint size, diamond labs vertical adaptor, 32degrees expansion chamber, shocktech drop, gereric WGP style bottomline adaptor and macroline throughout. My sourse of gas is a 16oz CO2 bottle. I have the greatest confidince that the gun will pull through, but having your gun crap out in the middle of a firefight is the pits. Can anyone give me some advice?

[banzaimf]

It sounds to me like an issue in the on/off somewhere. The first thought is the on/off pin. On the bottom, are there swirl marks or is it sanded

[ShinyGuy]

It sound like the regulator piston isn't moving freely. Since you got the gun used I'm assuming you don't have the manual or video. Give AGD a call and they will send you both of these. Dissasemble the regulator portion of the valve and check for any corrotion or debris that would prevent the piston from moving freely. Clean, reassemble and regrease the regulator (check the manual for the correct type of grease).

If that doesn't solve the problem it is also posible that something is wrong with the on/off (perhaps assembled incorectly). A thourough cleaning should fix any problem there (but it sounds more like the reg).

If you still can't nail it down send it it to AGD and they'll fix you up.

[Havoc_online]

the regulator piston isn't moving freely

You mean the reg valve pin? The piston doesnt move.

If you have checked all your o'rings and made sure that everything is installed properly, it may very well just be a case of liquid Co2 in the valve causing it to freeze up. Expansion chambers are not very dependable, the best way to keep Co2 out of your valve is to get your hands on a Palmer Stabilizer. Of course the price of one is about the same as buying a cheap nitro tank, even cheaper if you sell your Co2 tank and expansion chamber to get one.:)

Another thing you may want to look for is 1/16"(credit cards thickness) of a gap between the back of the trigger and the trigger rod when the marker is gassed up. This will show you if your trigger rod length is right so you can make full trigger pulls.

*edit* hitech is right, it moves about .005" on a classic and .125" on a RT... I was under the impression only the valve pin moved, I was wrong.

[mountainbob84]

which part?

Ok, so it's probably either the reg valve pin or the on/off, but which parts are these?

[Dayspring]

Take a jog over to www.airgun.com

They have technical diagrams of all the valves, as well as the store so you can buy replacement parts (which gives you an up close & personal look at some of the parts in the diagrams)

[hitech]

Originally posted by Havoc_online
...The piston doesnt move.

Sure it does, just not very much. When the pressure on the reg piston increases it pushes against the reg spring pack and allowes the reg pin to seal against the reg seat. If it sticks, you will have velocity problems.

[mountainbob84]

Whoops!

thanks Dayspring, figured out what was what and went to grease up my valve pin only to find that I have no regulator seat, it just wasn't there. I'm incredibly suprised my marker even fired at all! thanks to all who responded, I'll go grab a seat and I would assume that should fix the problem.