I have a 1977 Crestliner with 115 HP Johnson. I have owned this boat for about 15 years. Purchase it from the orignal owner. He used it only in fresh water. I use it in salt water only about 2 weeks a year. Never left in the water overnight. Flushed after every use. I want to replace the impeller due to time. My question is should I replace the water pump or only the impeller. The engine has never overheated. The five bolts on the lower unit are not frozen. What is the process to remove and replace the lower unit and impeller kit. Thanks Nick
