There seems to be a little confusion about damper plates here. Velvet Drives normally use a damper plate to connect the flywheel of the engine to the splined input shaft of the transmission. The damper plate looks somewhat similar to a car or truck
clutch disk, but bolts directly to the flywheel. The center of the damper plate has springs (like a
clutch disc) that absorb the engine impulses which makes life easier for the transmission. Before you do anything drastic, check the idle speed of your engine with a good digital tackometer. Dont trust the accuracy of your boat tack. I learned this lesson the hard way(expensive way) . I had a converted Mercedes auto engine in a
steel boat. It was a very good reliable set up, but rattled like hell at an in gear idle. Being an uninsulted
steel boat you could hear it for a hundred yards. I sailed like that for lots of miles, but hated manuvering in harbors becouse of the noise. At just above an idle it smoothed right out. I was told about bad damper plates by other cruisers and decided that I had better change it. I pulled the trans, and ordered a new damper plate from
Florida. The old one didnt look bad to me, but I changed it anyway. The end result was the same damn noise. Finally I met a cruiser that had worked in a
marine engine shop before cutting the
dock lines, and he came over and listened to the engine, and said the idle is too slow. We set the idle up about 100
rpm and everything was smooth. It didnt make much differance on the slight clunk when putting it into gear and
solved the problem. Becouse this was done with much sweating in the tropics it was a lesson I remember well. If it turns out that your idle is correct, I would still set it up a little to see if that solves it. If that doesnt solve it, go
head on and start changing things, but I always try the cheep simple things first. Good Luck._____Grant.