Need some pro advise....

[Rawze]

Your very lucky that your problems were not much much worse.

Did you have the key-way pin aligned in the damper properly? It sounds like the damper was not seated all the way. - If not, then the whole damper would not be seated properly and will suddenly come loose after finally slipping until it dropped into the key-way.

Also, If you have performed an overhead valve adjustment with the new damper, it not in the key-way properly, then the overhead valve adjustment could be incorect too. Just something to think about.

Excess anti-sieze is an unlikely a possibility at 130 ft-lbs but can happen? That is quite tight. Are you sure your torque qrwench was not on 130 Nm instead?.

Double check all that stuff and when it comes to anti-sieze, I always use only just enough to turn the the threads a bit grey and not much more. It really does not take much.

Same thing if you are using lock-tite. It does not take very much and in fact, lock-tite works better if you let it completely dry into the threads before installing the screw. using too much will make parts expand as the stuff dries and create problems.