My 1989 85hp Force developed an odd intermittent vibration type noise - or at least that's the best description I can think of - except louder than you would expect from vibration. It's only when in gear at low speed in fwd and occasionally in rev. No noise when in neutral. The faster the speed the less the noise. At mid-throttle and higher I cannot hear any noise - of course the engine noise could be masking it. There is no apparent loss of power when the noise occurs. This started suddenly last weekend. I trolled for 20 minutes then shut down for maybe another 20 mins. Then started up and moved at high speed for 5 minutes, then shut down for 20 minutes. Then when I started up again the noise started. I believe it's lower unit related because there's no noise in neutral. The lower unit has bee serviced in the past year and lube is good. I have not yet drained any to see if there's metal particles. What's got me baffled is the intermittent nature of the noise. It comes and goes for a few seconds at a time. I've got a video of the engine making the noise but I'm not sure if I can post it here (it's 250MB). I can strip off the audio portion and post here later.
