WREKS
Jetboaters Lieutenant
- Messages
- 1,167
- Reaction score
- 474
- Points
- 167
- Location
- Port Saint Lucie, Florida
- Boat Make
- Yamaha
- Year
- 2007
- Boat Model
- SX
- Boat Length
- 23
Good to be here. I have received and continue to receive much helpful and encouraging information from all the members contributing to the forums. I hope to be one of those members.
I love the water and boats. I got a jet boat for two reasons: I would not destroy props like I did on lakes up in Wisconsin and I thought it would be friendlier toward the creatures like manatees below the surface. I got twin engines for power but also for some assurance to get back to shore if one failed . Most of our (my wife and I) cruising has been on the Indian River Lagoon. Our boat is twelve years old but engines have less that 100 hours. Of course, we do not use our boat enough; but when we want to and we cannot-that is what this post is about.
Last time we went out, the port engine had the 'milky oil syndrome', and starboard engine was going into limp-mode after high temperature shutdown. I determined, the engines would have to be removed, one at a time, to look for the problems. The 2007 SX230HO is not easily worked on without pulling engines. I had never done this, so over the course of several months, I was able to fabricate a gantry crane in order to remove and reinstall the engines.
On the port engine, I replaced the cooling water pipe O-ring . I also eliminated the sand and corrosion in the manifolds and exhaust pipes. I did not remove the port cylinder head. But I think I may have to. The following will explain why.
I then took on the starboard engine overheating problem. While running on the hose, it was overheating after a few minutes and dropping into limp mode. I pulled the engine, replaced the engine and exhaust thermos switches because they tested out of spec, reinstalled the engine, and started it. That did not matter. It was still overheating. What finally convinced me to pull the engine AND remove the cylinder head occurred while running it on the hose again. I choose a spot on the cylinder head to take a temperature reading. That spot was a little nub of metal just above the exhaust port for Cylinder #1 and under the valve cover. Just before dropping into limp mode, the engine temperature rose from 150° F to 216° F in less than a minute. I got this reading using a IR temperature sensor. To make sure that the reading was not some sort of aberration, I started the port engine and took the reading at the same place on the cylinder head. It was and stayed below 140°F. I was convinced. The engine had to come out and the head had to come off. I did not want to do this, but I did not see any other way.
The cylinder head was clogged both above and below the head gasket. The water jackets surrounding the cylinders were impacted with a sand mix close to cement, especially around cylinders #1 and #2. I used pic tools and vinegar to loosen the buildup. I thought of what it takes a dentist to remove plaque below the gum line. Here are some before and after pictures. I hope this takes care of the overheating problem.
I always thought saltwater was the culprit. Now I am beginning to think that once sand gets forced into the water jackets, it is not easily removed, especially after building up over the years. Shallow water encounters giving the cooling system any opportunity to vacuum the bottom seem to be a very normal occurrence for most of us. I will definitely try the high pressure, closed loop cleaning suggested by CrankyGypsy. Like many others, I have had overheats from the very beginning. And I know the YDS does not register but a few of them.
I have to put the engine back together and see if there is any change. One must not get too confident. I hope these pictures come through. I have a question to ask. I hope it does not sound like a dumb one. The existing head gasket is a multilayer steel gasket. Do you think I could temporarily reuse it just in NoWake mode to see if my overheat issue is resolved? Thank you for any all input.
I love the water and boats. I got a jet boat for two reasons: I would not destroy props like I did on lakes up in Wisconsin and I thought it would be friendlier toward the creatures like manatees below the surface. I got twin engines for power but also for some assurance to get back to shore if one failed . Most of our (my wife and I) cruising has been on the Indian River Lagoon. Our boat is twelve years old but engines have less that 100 hours. Of course, we do not use our boat enough; but when we want to and we cannot-that is what this post is about.
Last time we went out, the port engine had the 'milky oil syndrome', and starboard engine was going into limp-mode after high temperature shutdown. I determined, the engines would have to be removed, one at a time, to look for the problems. The 2007 SX230HO is not easily worked on without pulling engines. I had never done this, so over the course of several months, I was able to fabricate a gantry crane in order to remove and reinstall the engines.
On the port engine, I replaced the cooling water pipe O-ring . I also eliminated the sand and corrosion in the manifolds and exhaust pipes. I did not remove the port cylinder head. But I think I may have to. The following will explain why.
I then took on the starboard engine overheating problem. While running on the hose, it was overheating after a few minutes and dropping into limp mode. I pulled the engine, replaced the engine and exhaust thermos switches because they tested out of spec, reinstalled the engine, and started it. That did not matter. It was still overheating. What finally convinced me to pull the engine AND remove the cylinder head occurred while running it on the hose again. I choose a spot on the cylinder head to take a temperature reading. That spot was a little nub of metal just above the exhaust port for Cylinder #1 and under the valve cover. Just before dropping into limp mode, the engine temperature rose from 150° F to 216° F in less than a minute. I got this reading using a IR temperature sensor. To make sure that the reading was not some sort of aberration, I started the port engine and took the reading at the same place on the cylinder head. It was and stayed below 140°F. I was convinced. The engine had to come out and the head had to come off. I did not want to do this, but I did not see any other way.
The cylinder head was clogged both above and below the head gasket. The water jackets surrounding the cylinders were impacted with a sand mix close to cement, especially around cylinders #1 and #2. I used pic tools and vinegar to loosen the buildup. I thought of what it takes a dentist to remove plaque below the gum line. Here are some before and after pictures. I hope this takes care of the overheating problem.
I always thought saltwater was the culprit. Now I am beginning to think that once sand gets forced into the water jackets, it is not easily removed, especially after building up over the years. Shallow water encounters giving the cooling system any opportunity to vacuum the bottom seem to be a very normal occurrence for most of us. I will definitely try the high pressure, closed loop cleaning suggested by CrankyGypsy. Like many others, I have had overheats from the very beginning. And I know the YDS does not register but a few of them.
I have to put the engine back together and see if there is any change. One must not get too confident. I hope these pictures come through. I have a question to ask. I hope it does not sound like a dumb one. The existing head gasket is a multilayer steel gasket. Do you think I could temporarily reuse it just in NoWake mode to see if my overheat issue is resolved? Thank you for any all input.
