Crankshaft dampner

[ynot]

What's your idle rpm at? In my experience anything below 700rpm an they will vibrate a bit, my 871 an this 870 I have now were both like that. I was in a buddies truck with a new x15(bone stock) an it was set down at 600 an was vibrating the interior so bad it was embarrassing for a 120k mile w9, I bumped his idle up too 725 using the cruise switch it helped tremendously.

too check the vibration damper just put both hands on the side of the valve while its idling, an feel for a mismatched shake, the worse the damper gets the more noticable it is, itll kinda feel like the motor is moving in an S pattern with the front of the motor shaking more an the rear is being pulled along for the ride