On my 1990 Chriscraft 20', with an OMC 4.3L HO, the trim gauge on the dash is wrong. All the way down it reads about 1.25, when it should read 0. I have the service manual, and it doesn't say anything in there about it. It may be an adjustment on the gauge, not the outdrive? If so, what is the procedure? I boat often in shallow water and want to make sure that I am not cruising along with the outdrive up too far.