Vibration

[War Eagle]

I have twin, gas, 454 Merc inboards (Vee Drive) on my flybridge & have a new very slight vibration in port engine. I hauled the boat this week with the following observations. Props are like new (had them checked), Shafts are straight (0.002 runnout), cutlass bearings like new, no strings/ropes tied around shafts, coupling alignment (in water) is dead on spec, rudders in alignment, and absolutely no visible damage anywhere on bottom of boat. Engine mounts are tight. So, I plan to do a tuneup next (2 yrs since last) because the vibration is only noticable between 2000 & 2800 RPM. At idle, or at speed it is very smooth. No water in gas (Racors). You feel the vibration most on the flybridge, & when you place your hand on the engine, either at coupling/tranny, or on top, it is hard to feel any vibration, but you can see where the shaft seal is, that the rubber boot is shaking. This is a new vibration as we hit something in the water (albeit not hard) and it could be a little parinoia, but both the admiral & I do notice a difference. We have already put over a 100 hrs on boat this season. We are currently doing a year long trip & are visiting in port right now, so we ahve 3 weeks to figure this out before we gat back on the road.