my tecumseh vtwin again-first issue -valve clearance

[38racing]

It's tvt691 on the zt50 I recovered from fire damage. I actually didn't get it out this year until last week. Cut for about 15 minutes and engine died. end result was the exhaust rocker on left side came loose. It requires a crowfoot 1/2 inch to tighten lock nut. I didn't have one last year so used regular wrench as best I could. I now have the crowfoot but I worried that when wrench clicks at 120 in lbs if it's due to proper torque or binding of the crowfoot against something. The setup is a rocker bolt with lock nut against head where bolt threads in. There is a serrated washer between lock nut and head. If it fails again my plan is to add a 2nd nut on the bolt. After doing normal lock of original nut I'll put loctite on face of the lock nut the threads between it and the added nut. Then I'll torque the 2nd nut against the original. Any thoughts. Meanwhile I have another issue in separate thread.