Tuning .30 Bobcat dumping tank.

I'd try and get to the valvepin cap thing and unscrew it to pull out the valve pin and check to see if everything is ok. Should be right below the barrel and 5mm iirc. That's how it is on royale and boss anyways. I know the bobcat has some differences.

I bet if the valve seat is damaged it'll come out partially on the stem or leave marks on the delrin part on the valve pin. Telling you the valve seat broke.

Is it leaking out the side holes of the block where you can see the tip of valvepin? You can also stick a wood dowel or something and gently pry against the valve pin it should be spring loaded with no air in block and be movable smoothly.
 
  • Like
Reactions: Ezana4CE
I'd try and get to the valvepin cap thing and unscrew it to pull out the valve pin and check to see if everything is ok. Should be right below the barrel and 5mm iirc. That's how it is on royale and boss anyways. I know the bobcat has some differences.

I bet if the valve seat is damaged it'll come out partially on the stem or leave marks on the delrin part on the valve pin. Telling you the valve seat broke.

Is it leaking out the side holes of the block where you can see the tip of valvepin? You can also stick a wood dowel or something and gently pry against the valve pin it should be spring loaded with no air in block and be movable smoothly.

+1, , it could also be the cylinder seal or the Regulator seal blew out, those are close to the trigger., looks like you are going to need to take the gun apart, best replace all seals while you have it apart.
 
? Is this the pin your about Glem 
C8573F0D-D73B-403D-AE53-F6120F279C4A.1624924464.jpeg

 
Your valve pin is sticking. I bet if you shot thru a chronograph you will see erratic spreads. My questions to you, as I have personally witnessed this-

1. Was your gun at its max fill(or over filled) and left out in the hot weather or stored in a hot area, where air inside the gun expands?

2. When was the last time you had the gun apart for a lube up?

3. Your air source? Clean, filtered air, or unfiltered from a hand pump? Do you take the extra care and make sure your fill hoses, probes, etc, are always protected from debris and dust?



If your valve stem is dry and gritty, it will cause sticktion, and will cause the problems you’re describing. 

Hot, over pressurized air will push on that valve stem against the seat, which could damage either the seat or that tiny o ring on the stem. Either will case a leak out the barrel.

not even going to go over using unfiltered air cause you know what that’ll bring into the gun. Pull that valve stem out, polish up the poppet, replace the o ring. Remove the valve seat and inspect how it seats against the valve stem poppet. If all good, replace the valve seat o ring and pop it back into place. Add a light lube of silicone grease to the valve stem and it’s o ring before re inserting it. 

Behind the valve stem, is a spring. The access bolt to remove the valve stem has two seals inside of that that the spring sits upon. Check and or replace those also, while you’re there. When refilling your gun, do it in three stages, do not fill all at once. Allow the air to cool inside the gun before adding more.
 
  • Like
Reactions: Ezana4CE