I have a 1979 70 hp johnson jet outboard. I need to buy a new impeller for the jet unit, but I have a problem. My impeller is held from spinning on the shaft by a rectangular woodruff key that fits into a slot in the shaft. My dealer tells me that the only impellers that he can get are now made with a rounded groove for the key and are make to fit onto a shaft with a flattened side. Do I have to grind a flat side into my shaft or can I get a modified key or an old style impeller? Thanks for the help<br /><br />-Joshua
