I'm not sure if cyclical is the correct word, but here is what I am experiencing. Quick back story. This winter I removed the engine, replaced the engine mounts, cutlass bearing, and prop shaft. I aligned the engine in the water and got it within .030 all around. I cruise comfortably around 2100 rpm with no vibration. When I push it harder to above 2400 to red line there is a vibration /buzzing in the hull that I start to feel. The weird thing about it is, it is not constant but goes in 2-3 second intervals. Vibration for 2 seconds, then smooth for 2 seconds, wash rinse and repeat. If you vary the rpm it doesn't seem to change the duration but more changes the strength of the vibration.
I would understand that something is off alignment wise if it was constant, but where it is on and off, I'm not sure what to make of it.
I would understand that something is off alignment wise if it was constant, but where it is on and off, I'm not sure what to make of it.