I have three 075/6's that I use for milling. I had one that started to act up so I replaced it with my back up power head. It's a fresh rebuild and starts/idles great. Once you rev it up it looses all power. It might be running out of fuel, but I wanted to start with the compression release valve. The valve had been sticking and I was hearing a pft-pft-pft sound that could indicate that it's leaking. The new valve had a hex to receive a wrench, but I can't figure out how to access the hex on the installed valve. Suggestions are appreciated!