Now that it's apart, replace all of them. You will need to work from a manual. Obtain one before you continue. You can get an aftermarket one from Iboats, or borrow one from the libary. You can get (preferred) OEM ones from the following places:<br />TheOutboardWizard<br />Mastertech<br />Marine Engine<br />Ken Cook <br />You can sometimes find OEM ones on ebay for a fraction of the price of a new reprint.<br /><br />It seems there was a change in the lower unit part way through the '57 model year that makes the lower unit reseal kit part number change. Be sure you're getting the correct kit when you buy it.<br />Are you certain it's a '57?
