Can't fix my gun

[mosesisback19]

I have a 68 classic. When I gas it up it shoots fine for the first 5 to 10 shots, then it shoots a burst of CO2 and takes a while to recharge for another shot. Adjusting the velocity doesn't help. All seals are good. I went through and replaced all of them. The only thing I haven't tried yet is putting in a bigger power tube spacer. My friend is having the same problem even after he replaced the spacer.

Any ideas? I'm about ready to just send it in and have it taken care of, but I want to see if anyone out there has an idea first.

[Smoothice]

are those 5-10 shots under rapid fire? You could be freezing the gun up when using co2.

If it is liquid co2 you could:

install the tank vertically.

or

Use an expansion chamber - and use a anti siphon tank if mounted horizontally (anti siphon tanks need to be set up for the marker you are using. It may not work when switching from one marker to another)

or

Get HPA

Also, I believe the powertube spacer would have more to do with leaking down the barrel. Someone correct me if I am wrong.