Re: Yanmar 3gm raw water pump
I have found the only way to change the impeller is to just remove the pump. As I recall there are only a couple of bolts to remove the pump, but I don't remove the hoses. To make the change even easier, you might consider a "Speedseal". If you are not familiar with the product, it is a brass plate that replaces the the steel cover. It has fasteners you can tighten/loosen by hand, and you are much less likely to loose them in the bilge.