Salam to all brothers
On engine idle, if I open my bonnet and place my hand on air filter plastic box I feel harsh vibrations especially if engine is cold. These vibes are quite strong but their oscillatory motion is not large that is why without placing a hand you will not notice that engine is vibrating. Due to these vibes slight vibration in steering wheel are also felt. These vibes disappear at 2k rpm and beyond.
Engine mounts are fine. Carb mixture settings are correct and plugs run clean dark grey. Air filter is almost new. There is no other issue in the engine. It is over hauled engine but vibes were there on the same extent before engine was rebuilt.
Any ideas and suggestions why are these vibration? If I turn on AC these vibes become slightly more pronounced.
I myself think it is related to base timing ? as my centrifugal advance timing (the one done at distributor) is at max and timing belt is brand new.