I 'm having trouble with my RT Pro going into run away. It hasn't given me any problems for years and now it is running away. I have an X-Valve with LX and ULT. I don't remember the settings for the X-valve, but the ULT has 4 shims. Additionally, I'm running it with a Centerflag Products Hyperframe.

I tried removing a couple of shims from the ULT, but then it wouldn't fire. Replaced the shims and running away. I then tried a longer bolt spring because it seems like the bolt might not be resetting and then it wouldn't fire. I increased the valve pressure and it would work a little bit.

This marker has been in its current configuration for probably 10 years or so. I understand that the spring could have fatigued or taken a set, but I would think that it would work with a longer spring then. Additionally, I inspected the sear and it looks fine.

Does anyone have any thought?