Hello, I am hoping to get some information if anyone could help...during the summer, my dad bought a boat from someone and we have been doing work on it (mostly cosmetics). It's a 1987 Searaider with a 4.3 OMC V6 with a cobra outdrive. We have taken it out about 4 times this summer, but back in July, while running at maybe 35mph, we heard a lough sound and then followed by a knocking sound. we assumed that we blew a cylinder, which is what the marina said as well. They said cylinder #3 blew and they're not sure what it is unless they take it apart. Unfortunately, its on the side with the gas tank, and would cost about 500 dollars to take it all apart and 500 to put it back together, not to mention what would need to be fixed, and we don't want to have them take it apart when we dont have the money to fix it. I dont know what it could be, my dad thinks it could be a lifter but he's not sure. However, today while I was covering the boat back up, I noticed a tube like structure under the outdrive that was not connected. I'm going to try to upload a photo of it, but I believe it to be the impeller to keep the water pumping through to the engine to keep it cooled. Now I am probably wrong but is it possible that the impeller (if thats what it is) disconnected and is causing the engine to overheat and is causing the knocking sound? The marina said there's no compression in cylinder 3, and I dont want to accuse them of lying, but they didn't mention anything to us about the impeller not being connected and we havn't done anything with the boat to cause it to disconnect. I know its alot of information, but I'm not sure what to do. My dad thinks he can take it apart himself, but to be honest I'd rather have someone with a lot of experience to do it, if thats even what it needs. If anyone has anything to contribute or any advice, it would be much apprectiated. Thank you for reading!
