Some VM68's have small exhaust ports in valve and reciever, causing low velocity and poor overall performance after installing PRO-COMPv.3 kit. Follow these instructions to remedy this problem. NOTE ALL VM68's NEED THIS MODIFICATION!

1) Check your gun buy removing the valve and use the supplied 3/16" drill bit and see if it will fit the large hole in the valve. If it does fit your probably in good shape but you should check the reciever hole and make sure it also 3/16". To do this you need to remove the set screw that is on top of reciever behind feed adaptor, sometimes it has to be heated to loosen the loctite, you don't need to reinstall the set screw it doesn't do any thing. Check if drill fits down through air passage, if it does every thing is OK, otherwise go to step 2.

2) Remove O-rings on valve and install it with the smallest hole in the 12 o'clock postion.

3) Use supplied 3/16" drill bit and drill down through reciever and valve, make sure you don't drill to deep into the opposite side of valve. Drilling it this way will give perfect port alignment.

4) Remove valve and deburr reciever where the upper bolt slides (any burrs will scar Delrin upper bolt) and where the valve goes so the O-rings won't get cut. You can put sand paper on a wood dowel or use a hone to do this. Wash reciever throughly!

5) Reassemble gun.