A few weeks ago I bought an '87 Baja Sunsport 196 with a 5.7L OMC Cobra I/O. I have only been able to take it out on the water once so far and everything worked great. The only problem I've run across is that the engine runs very cool. It never got over about 130 degrees, even when at WOT for a couple minutes. Running the engine in my driveway with muffs, the engine warms up in a reasonable amount of time, but still only hits about 130 degrees. I believe the gauge and sending unit are fine because the water hoses are just luke warm to the touch.
Now, it should be noted that I live at high elevation. Here in Cheyenne we are at about 6200 ft. The lake I ran on in Colorado is roughly 6000. Typically, an engine loses about 30% of it's power up here when compared to sea level. That would make my 260 hp 5.7L more like 180-190 hp. Is it possible that the engine is running cool because of the lack of air and diminished power? Or is it more likely that the thermostat is stuck open? I checked the timing and it was set at 14 degrees advance. I figure that's probably about right considering the manual says to run 10 degrees at sea level on higher octane (89) fuel. I'm running 91 octane.
Also, the boat didn't seem to want to go faster than about 45 mph (even after playing with the trim). That was based on the speedometer, which I realize isn't the most accurate thing in the world. However, most guys claim with the same engine/boat they can easily eclipse 60 mph. I've known a couple people with 4.3L Mercruiser engines that say they can run 45 mph up at this elevation with a similar-sized boat. The tach didn't work when I had my boat out, but I have since fixed that. I understand that running in the recommended RPM range will make a big difference, so that lack of information won't help. However, the boat does still have the original 14.5" 19 pitch aluminum prop installed. I am planning on taking it out again over Labor Day weekend, so I'll see what it's doing with a working tach.
Any ideas?
Now, it should be noted that I live at high elevation. Here in Cheyenne we are at about 6200 ft. The lake I ran on in Colorado is roughly 6000. Typically, an engine loses about 30% of it's power up here when compared to sea level. That would make my 260 hp 5.7L more like 180-190 hp. Is it possible that the engine is running cool because of the lack of air and diminished power? Or is it more likely that the thermostat is stuck open? I checked the timing and it was set at 14 degrees advance. I figure that's probably about right considering the manual says to run 10 degrees at sea level on higher octane (89) fuel. I'm running 91 octane.
Also, the boat didn't seem to want to go faster than about 45 mph (even after playing with the trim). That was based on the speedometer, which I realize isn't the most accurate thing in the world. However, most guys claim with the same engine/boat they can easily eclipse 60 mph. I've known a couple people with 4.3L Mercruiser engines that say they can run 45 mph up at this elevation with a similar-sized boat. The tach didn't work when I had my boat out, but I have since fixed that. I understand that running in the recommended RPM range will make a big difference, so that lack of information won't help. However, the boat does still have the original 14.5" 19 pitch aluminum prop installed. I am planning on taking it out again over Labor Day weekend, so I'll see what it's doing with a working tach.
Any ideas?
