I have a sea ray 280 sundancer with twin 4.3 V6 engines. Nobody seems to be able to tell me what rpm this baby should cruise at for lets say a 60 mile trip. What do any of you suggest for a cruising speed? I have been running it around 35 mph and 4000 rpm's, is that OK? What about full throttle? Would it hurt anything?
Keep it under 3300 RPMs or you will pay If you cruise at much more than 3200 RPMS, you will reduce the life of your engines. Get on plane and reduce RPMS to just enough to keep you on plane. That will be around 3000 - 3400 RPM. The closer to 2900 the better. If you have 4 bladed props, you should not have to run it above 3200 for this.
Sorry it took so long for this response. Hopefully you've learned the answer by now, but here it is for the next guy. I've always recommended running at 80% of max up to no more than 90% with a gas motor. Those motors should max at about 4600. You'll probably find 3600-3800 to be a sweet spot for that boat. When your bow is sticking up (mid-range before getting on plane) that is the most inefficient spot, burns the most fuel and puts the biggest strain on the motor. Constantly running slow will clog the motor. Don't be concerned with equating RPM's and speed as the speed at a given RPM will change depending on the forces of wind, current, the amount of wirht you're carrying, etc.
