My 352(No735)has developed an annoying and very worrying trait. She has a 2003T Volvo. At 2000rpm she trundles along quietly at 6.2 knts. Push the revs up beyond that and she makes a noise like thunder - as if someone were hammering the hull with a rubber mallet. She is completely clean below the waterline - no weed/barnacles etc - she was lifted out last week - but still the trouble persits. The cutlass bearing was replaced six months ago and shows no wear and the engine mounts appear fine - also the prop was balanced at the same time. She has a SPURS rope cutter fitted. Given that in neutral the engine will achieve 3000+ rpm like a sewing machine - even if a seventeen stone man stands on it - I am lost for a solution. Can anyone venture any suggestions please?

By Peter Brown on Sunday, August 25, 2002 - 12:35 pm:

Could it be the Spurs cutter? Is it properly aligned relative to the holding block? Are the sound deadening plugs in place? Might the bearing be worn?