I am having a problem with the engine overheat alarm (digital guages) sounding on one of my 2000 Yamaha 200 HPDI engines.
The problem seems only to occur at higher RPMs (>3,500)
The first time I experienced the problem the port engine was running rough (lots of vibration) and was having trouble reving up beyond ~ 3,000 RPM (RPM reduction mode?). Then on the way back from our run out to the engine alarm sounded.
The second run I was able to run the RPMs up beyond 3K, however I do recall that the port engine took a lot more throttle than the SB to get there. I was very rough that day, so this is not a precise analysis.
On the last run I first tried to get the boat up on plane the port engine would not rev up beyond 2,500 to 3,000 RPM (no alarm sounded). I shut both engines down and re-started and then was able to run up to 5,000 RPM for a while. After a few minutes running at 4,700 the engine alarm sounded again.
Listed below are the items I have addressed:
1. Thermostats- replaced
2. Pressure relieve valves( poppet valve)- replaced
3. Water pump impeller – replaced
4. Heads removed and water jackets checked - clean as a whistle!
5. Replaced fuel filter cannisters (Raycors)
Given the above repairs, it does not seem that it is a cooling problem. Could it be a problem with the oil injection?
Per
http://www.marineengine.com/question/edit.aspx?PID=38227856&P=1&au=True
The problem seems only to occur at higher RPMs (>3,500)
The first time I experienced the problem the port engine was running rough (lots of vibration) and was having trouble reving up beyond ~ 3,000 RPM (RPM reduction mode?). Then on the way back from our run out to the engine alarm sounded.
The second run I was able to run the RPMs up beyond 3K, however I do recall that the port engine took a lot more throttle than the SB to get there. I was very rough that day, so this is not a precise analysis.
On the last run I first tried to get the boat up on plane the port engine would not rev up beyond 2,500 to 3,000 RPM (no alarm sounded). I shut both engines down and re-started and then was able to run up to 5,000 RPM for a while. After a few minutes running at 4,700 the engine alarm sounded again.
Listed below are the items I have addressed:
1. Thermostats- replaced
2. Pressure relieve valves( poppet valve)- replaced
3. Water pump impeller – replaced
4. Heads removed and water jackets checked - clean as a whistle!
5. Replaced fuel filter cannisters (Raycors)
Given the above repairs, it does not seem that it is a cooling problem. Could it be a problem with the oil injection?
Per
http://www.marineengine.com/question/edit.aspx?PID=38227856&P=1&au=True