Sorry for the long post but I feel you need all the background info to give me good advice ..
Ok so I find the boat I want (I am a newbie to boating and this is my first boat) and make the deal with the Seller, The boat is a 1993 Sea Ray 290 with a 7.4 IO and a Bravo 2 outdrive.
I set up a sea trial (had to put it back in the water) and a surveyor . Everything looks great and we take it out for a ride. The surveyor wants to run the boat at 3000-3200 for a bit to check oil pressure and eng temps - all is good after 10 15 mins
He then wants to bring it up to 4000 -4200 but just for a short time, after about 2 mins an alarm goes off and no one seems to know what it is. We check oil and it's good but the eng temp is up around 210-220? so we back it down and limp back to the dock.
Once we get back the temp drops to around 170? and after shutting it down and letting the eng cool then restart the temp is at 150?. The weather turned bad and we cannot go back out. The seller seems to think that it is either the impeller or the thermostat and is willing to change them both.
I meet up with the seller 2 days later and we install a new 140? thermostat and a new impeller, the old impeller looked like it was brand new
Started it up , checked for leaks and got it up to temp , about 5 mins to get to 150.
Once we had it to temp we took it out for a run, ran about 1000 rpms and 150? to get out of the channel, about 10 mins and once out I have him run the boat for 5 min intervals each at 1500, 2000, 2500, 3000, 3500, 4000 rpm's all the while I am checking temps at the dash, top of thermostat, RT and LF mainfolds and RT and LF risers ( with a laser heat gun) during all the RPM ranges and it never went over 185 degrees. Finally stepped up to WOT which was 4300 rpm's for about 3 mins and the temps hit 190. no alarms and no problems. After the WOT dropped down to cruise at 3000 rpms and the temp dropped to 170. I guess we fixed it, I am happy with the results , so I buy the boat.
I have to wait to pick it up. It is like 40 miles from home and to big to trailer. I pick up the boat with My Brother in-law ( very experienced boater) 5 day later. She starts fine and leave, need to get gas and that all goes well, get out of the channel and in about 10 mins at around 3200 rpm?s the alarm goes of again!
We drop the rpm?s and the temp also drops to about 165-170? but we have to keep the rpm?s no higher then 1500 and can get over 8 knots. I have no chosse I have to get it home so we limp along and I will deal with it when we get home. We now have a 4 hr ride instead of an hour and a half. During the first 2 hrs I try to get the speed up but can?t go over 2000 rpm?s without the temps going to 200?
So we are like 10 miles from home and like an hour and a half left when I get an idea, push the rpms up to get the boat on plane, then back down the rpm?s and maybe I will be able to keep the temp down below 190?. I try it, get on plane, and the temps rise to 200 in about a min. I back it down and wait for the temp to drop to 170? and try again. Same thing happens but I am getting a lot further then to just limp along at 8 knots. On the third try the temps never goes over 170? and we get all the way home at 3200 rpm?s and like 27 knots. What gives? Why after all this time is it running like it should?
Finally get back to the dock and all is good. I don?t understand what is going on.
The very next day I decide to take the boat out and see what the temps are going to do.
The boat starts fine, warms up fine. I run for 2 hrs straight at all different rpm?s , cruise at 3000 rpm for like an hour, try to push it and bring rpm?s to 4000 for like 15 mins. And all the while the temp NEVER goes over 170?
The boat ran perfect and I don?t know what to do next. I was thinking it was manifolds and or risers considering they are about 6 years old.
Does anyone think they know what is happening or have had this problem?
Please help
Thanks
Studman
Ok so I find the boat I want (I am a newbie to boating and this is my first boat) and make the deal with the Seller, The boat is a 1993 Sea Ray 290 with a 7.4 IO and a Bravo 2 outdrive.
I set up a sea trial (had to put it back in the water) and a surveyor . Everything looks great and we take it out for a ride. The surveyor wants to run the boat at 3000-3200 for a bit to check oil pressure and eng temps - all is good after 10 15 mins
He then wants to bring it up to 4000 -4200 but just for a short time, after about 2 mins an alarm goes off and no one seems to know what it is. We check oil and it's good but the eng temp is up around 210-220? so we back it down and limp back to the dock.
Once we get back the temp drops to around 170? and after shutting it down and letting the eng cool then restart the temp is at 150?. The weather turned bad and we cannot go back out. The seller seems to think that it is either the impeller or the thermostat and is willing to change them both.
I meet up with the seller 2 days later and we install a new 140? thermostat and a new impeller, the old impeller looked like it was brand new
Started it up , checked for leaks and got it up to temp , about 5 mins to get to 150.
Once we had it to temp we took it out for a run, ran about 1000 rpms and 150? to get out of the channel, about 10 mins and once out I have him run the boat for 5 min intervals each at 1500, 2000, 2500, 3000, 3500, 4000 rpm's all the while I am checking temps at the dash, top of thermostat, RT and LF mainfolds and RT and LF risers ( with a laser heat gun) during all the RPM ranges and it never went over 185 degrees. Finally stepped up to WOT which was 4300 rpm's for about 3 mins and the temps hit 190. no alarms and no problems. After the WOT dropped down to cruise at 3000 rpms and the temp dropped to 170. I guess we fixed it, I am happy with the results , so I buy the boat.
I have to wait to pick it up. It is like 40 miles from home and to big to trailer. I pick up the boat with My Brother in-law ( very experienced boater) 5 day later. She starts fine and leave, need to get gas and that all goes well, get out of the channel and in about 10 mins at around 3200 rpm?s the alarm goes of again!
We drop the rpm?s and the temp also drops to about 165-170? but we have to keep the rpm?s no higher then 1500 and can get over 8 knots. I have no chosse I have to get it home so we limp along and I will deal with it when we get home. We now have a 4 hr ride instead of an hour and a half. During the first 2 hrs I try to get the speed up but can?t go over 2000 rpm?s without the temps going to 200?
So we are like 10 miles from home and like an hour and a half left when I get an idea, push the rpms up to get the boat on plane, then back down the rpm?s and maybe I will be able to keep the temp down below 190?. I try it, get on plane, and the temps rise to 200 in about a min. I back it down and wait for the temp to drop to 170? and try again. Same thing happens but I am getting a lot further then to just limp along at 8 knots. On the third try the temps never goes over 170? and we get all the way home at 3200 rpm?s and like 27 knots. What gives? Why after all this time is it running like it should?
Finally get back to the dock and all is good. I don?t understand what is going on.
The very next day I decide to take the boat out and see what the temps are going to do.
The boat starts fine, warms up fine. I run for 2 hrs straight at all different rpm?s , cruise at 3000 rpm for like an hour, try to push it and bring rpm?s to 4000 for like 15 mins. And all the while the temp NEVER goes over 170?
The boat ran perfect and I don?t know what to do next. I was thinking it was manifolds and or risers considering they are about 6 years old.
Does anyone think they know what is happening or have had this problem?
Please help
Thanks
Studman
