Sea Buzzard
Cadet
- Joined
- May 3, 2010
- Messages
- 16
I have a 2006 4.3 Mercruiser in a Trophy with a closed system. The raw water comes in thru hull. Last fall I had an overtemp problem running it on the hose. I put it in the water and the problem went away. I figured something was clogging the passages and it was cleared.
I ran it on the hose 2 months ago and it ran fine. This week I started it on the hose and had no water coming out the transom. I disconnected the hose inside the bilge and ran the water hose directly to it. Same problem. I then disconnected the hose coming off the top of the port riser going into the heat exchanger and connected the water hose directly and water flowed out the starboard side of the transom. Same thing on the opposite side.
I put everything back together and had the same problem. I ran the motor up to 3000 RPM and started getting water to flow out of the transom. I know, not the smartest thing to do, but I had to check.
I then put the boat in the water and started it and backed away from the dock. Was checking a few other things since this was the first time in the water in 7 months and the temp started climbing. I reached over the transom to check for flow and again nothing. I shut down the motor to cool it down and after about 20 minutes I started it and put it in gear and brought the RPMs up and the temp went down. Reaching over the transom, I could feel hot water. Ran it at 4400 RPM for 20-30 minutes with no problems. Back down to idle and overheating again. I ran it back to the ramp and put it on the trailer.
Back at the house, same thing. I have separate water hoses going to the thru hull and sterndrive. Waterflow out of the sterndrive is good. Zero suction at the thru hull. I have had the boat 6 years (139 hours) and never replaced the impeller, so yes that is going to be changed. I should know better, but I hope there is an easy fix for this. The circulating pump is on the bottom port side and impossible to reach.
Does the thru hull and sterndrive water have anything to do with each other? They appear to be separate systems, but I'm not positive. Does the circulating pump have an impeller similiar to the sterndrive? The boat is only used in saltwater, but is flushed after every outing. I just want some direction starting with the easiest/most likely problem. I don't want to spend hours and hundreds of dollars when it could be something simple. I have a bad habit of trying the hardest, most expensive things first only to find out it was something cheap (relatively speaking) and easy.
Sorry to give so much info, but would rather give to much instead of not enough.
I ran it on the hose 2 months ago and it ran fine. This week I started it on the hose and had no water coming out the transom. I disconnected the hose inside the bilge and ran the water hose directly to it. Same problem. I then disconnected the hose coming off the top of the port riser going into the heat exchanger and connected the water hose directly and water flowed out the starboard side of the transom. Same thing on the opposite side.
I put everything back together and had the same problem. I ran the motor up to 3000 RPM and started getting water to flow out of the transom. I know, not the smartest thing to do, but I had to check.
I then put the boat in the water and started it and backed away from the dock. Was checking a few other things since this was the first time in the water in 7 months and the temp started climbing. I reached over the transom to check for flow and again nothing. I shut down the motor to cool it down and after about 20 minutes I started it and put it in gear and brought the RPMs up and the temp went down. Reaching over the transom, I could feel hot water. Ran it at 4400 RPM for 20-30 minutes with no problems. Back down to idle and overheating again. I ran it back to the ramp and put it on the trailer.
Back at the house, same thing. I have separate water hoses going to the thru hull and sterndrive. Waterflow out of the sterndrive is good. Zero suction at the thru hull. I have had the boat 6 years (139 hours) and never replaced the impeller, so yes that is going to be changed. I should know better, but I hope there is an easy fix for this. The circulating pump is on the bottom port side and impossible to reach.
Does the thru hull and sterndrive water have anything to do with each other? They appear to be separate systems, but I'm not positive. Does the circulating pump have an impeller similiar to the sterndrive? The boat is only used in saltwater, but is flushed after every outing. I just want some direction starting with the easiest/most likely problem. I don't want to spend hours and hundreds of dollars when it could be something simple. I have a bad habit of trying the hardest, most expensive things first only to find out it was something cheap (relatively speaking) and easy.
Sorry to give so much info, but would rather give to much instead of not enough.
