A-5 no velocity no cyclone

Just purchased a used A-5 and the marker has very low power or velocity and the cyclone feeder wont advance. I'M using a fully charged  3a high pressure air tank that works fine on a JT, also have replaced all orings and lubed marker per instruction manuel. I'm thinking it could be a weak drive spring or a valve problem? The valve spring seams very stiff and the drive spring seams weak. Any help would be welcome and appreciated

Thanks RockDancer

The Guy, he stated hes using a 3A High Pressure Tank.

Double-check the tank - that's the first suspect.  Make sure that it is not just high pressure, but high OUTPUT pressure.  You should have at least 800psi from the tank.

Then take off any RVA's or stocks and put in a stock end cap.

If that doesn't help, get a new drive spring.

It could be the valve, but most likely an endcap/spring issue, IMO.

The reason so many are asking about the tank output pressure is that both the "power" (probably shot velocity) is low and the cyclone won't advance. If the VAS is open, but the valve isn't releasing enough gas, all available pressure goes to the barrel, with nothing left to be redirected to the cyclone. The cyclone is fed only off the air "blocked" by the VAS.

However, if the tank is a high output tank, my bet would be on the air path between the valve and the tank. I have read MANY posts of people reporting thread sealant inside the airpath. This creates an obstruction prior to the valve.

As a way to test this ... load and wait a bit, then try to fire multiple rounds. The first will fire normally, while any subsequent shots will be weaker and likely fail to cycle the cyclone. The reason is simple air starvation. The first shot was able to over time get enough air to the valve, but was unable to do so quickly. This was a common problem in old-school semi & full-auto markers on CO2 and was most commonly corrected by switching to syphon lines in the tanks to feed liquid into the valve (not the best option in today's markers).

Another way to test for this being the problem would be to remove the tombstone adapter and screw a tank directly onto the tombstone. If it is the air line, it should work fine, though I have read of threadsealant in the tombstone as well.

Please notice- he mentioned his air tank worked fine on his JT (Brass Eagle knock-off), which operates off of high pressure (may be lower than 800). However, even a tank putting out 700 psi will turn the cyclone. I would know because my HPA did put out only 700 psi when I bought it, my only problem was velocity not over 260, with horrible spikes in velocity.

There is a chance for air line blockage, but it sounds like to me the gun isn't aged enough or has received any custom work to warrant additional thread sealant or teflon tape.

One possibility is poor maintenance. I don't have much information on the actual gun, but it may be that it hasn't received oil for so long that the parts have already become damaged from excessive CO2 use, failure to oil, or failure to clean out old oil before dumping new oil in.

A good cleaning and inspection of all parts solves 98% of most Tippmann problems. All it takes is a peek at whats inside (the system is so simple, problems can be obvious).