am starting to restore a Merc mark 28 Iam haveing problems changing water pump. do you get to it by pulling power head or lower unit? this has that all in one shifter on tiller handle. some one gave this to me about a year ago and it had been setting in a shed for last 41 years and the guy was 97 years old he said he used it about five times and got into big boats and left it sit.It fired up on the 4 th pull and runs but doesnt pump water.any help would be greatly appreciated Thanks Mark
