ANOTHER GC190 exhaust rocker arm cracked problem.

[gwtx]

GC190 exhaust rocker arm cracked on pressure washer engine . There is a considerable amount of info available on the web about this, but I would like to see what the opinions/ideas are here on this forum. I Have read where it may be caused by the valve guide "backing out". That doesn't appear to have happened in this instance. Before reading about using a modified intake valve seal on the exhaust valve to prevent such,and ordering one
I then read where that's not a good idea due to having a "shimming" effect increasing tension on the spring. Not sure that would be a problem,,but,, Not sure what caused the breakage of the rocker arm to begin with . The
It got to where it was hard to pull the starter rope, and I checked the valve clearances, and the exhaust was a bit loose. I adjusted to .008" and it ran fine for a little while, then started bogging down,,until it died. I have had this machine for a long time, and it has served me well. It has run for extended periods washing side walks, patios, and mowing equipment. I would hate to see it go, but I can't stand to have it jerk my old arm off AGAIN.
I have the rocker arm and the valve stem seal on order, but since the guide had not backed out,, not sure if I want to modify and install the seal or not. Whatcha think? Thanks, Gary