Thanks to everyone who posted replies to the noisy exhaust on my tahoe, with a Mercruiser 4.3L. This past Memorial Day weekend the boat was taken out of the water on Thursday. Cause of noise found! Low and behold the exhaust hose came loose from the transom exhaust connection. I phoned the dealer where the boat was purchased to explain the finding. On Friday I brought the boat to them and I had it back Saturday morning. Apologies and away I went to a fun relaxing Summer weekend.
Jeff
Jeff