How hot is too hot.
Printed From: CorrectCraftFan.com
Category: Repairs and Maintenance
Forum Name: Boat Maintenance
Forum Discription: Discuss maintenance of your Correct Craft
URL: http://www.CorrectCraftFan.com/forum/forum_posts.asp?TID=26656
Printed Date: November-18-2024 at 10:43pm
Topic: How hot is too hot.
Posted By: OverMyHead
Subject: How hot is too hot.
Date Posted: June-26-2012 at 2:47am
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No not me, the boat. I am fighting an overheat problem. Running about 180 degrees at 2500 rpm. Ran around 160 last year. Has been hot since un-winterising. I have been running without a strainer in the basket for years, but the gasket is present and the basket is tight. I back flushed the tranny cooler and then from the tranny cooler to the lake pick up. I put in a new impeller but the old one looked great. I have inspected the hoses and tightened all the clamps with no improvement. I will inspect the thermostat next, and I bought a new in line strainer with the wire screen to install(Grainger, I love that place!). I want to check the engine temp with the thermoscanner, what part(s) should I target? How hot can I run the boat without doing damage? Will 180 do any harm or can I have a little fun if I put it in the water and still have the problem? Will dirty electrical contacts raise or lower the reading? What else have I missed? ------------- For thousands of years men have felt the irresistible urge to go to sea, and many of them died. Things got better after they invented boats. 1987 Ski Nautique |
Replies:
Posted By: GlassSeeker
Date Posted: June-26-2012 at 7:04am
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air leak somewhere ------------- This is the life |
Posted By: 8122pbrainard
Date Posted: June-26-2012 at 8:30am
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Dave, Resistance from bad connections will lower the reading on the gauge. Who's brand of impeller did you use? The OEM is best as there are reported problems with the Sierra. ------------- /diaries/details.asp?ID=1622" rel="nofollow - 54 Atom /diaries/details.asp?ID=2179" rel="nofollow - 77 Tique 64 X55 Dunphy Keep it original, Pete < |
Posted By: Waterdog
Date Posted: June-26-2012 at 9:30am
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180*f is fine 200 and over isn't. An engine will run about 20 degrees warmer than the t'stat. ------------- - waterdog - http://www.correctcraftfan.com/diaries/details.asp?ID=3896&sort=&pagenum=2&yrstart=1978&yrend=1978" rel="nofollow - 78 Ski Tique |
Posted By: OverMyHead
Date Posted: June-26-2012 at 11:38am
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Pete, It is a sierra purchased locally through a fairly reputable inboard sales and service dealer. The fact that it runs the exact same temp with either the old or new impeller installed makes me think that it is not the likely problem. Andy good to know about the 200 degree max. The thermostat is rated around 140 and it always ran 155 to 160 under load. I am also thinking air. I can focus on the suction side of the pump correct? And if I see no air going through the strainer than I should focus between the strainer and the raw water pump? ------------- For thousands of years men have felt the irresistible urge to go to sea, and many of them died. Things got better after they invented boats. 1987 Ski Nautique |
Posted By: TRBenj
Date Posted: June-26-2012 at 11:46am
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I agree with Andy on the safe temperature range. Above 200, I shut it down. I disagree with Pete about the gauge... while extra resistance on the temp sending wire may cause it to act as he describes, dirty connections on the power coming to the gauge will do the opposite. The undersized wiring to the dash of my '90 (combined with dirty connections, no doubt) causes the temp gauge to jump 20 degrees when I turn my lights on. I think you need to put the boat in the water and get a better feel for the failure mode. An overheat at idle and an overheat at speed are 2 very different scenarios. ------------- |
Posted By: N2Deep
Date Posted: June-26-2012 at 2:30pm
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double check you don't have pieces of the old impeller lodged in the T-stat housing. Mine was running hot with a new impeller and no air leaks. After pulling the T-stat housing I found about 15 pieces of old impellers lodged in there. When the pieces break off they have to go somewhere and could be restricting waterflow. ------------- 1991 SN pulled by a 2010 Tundra |
Posted By: OverMyHead
Date Posted: June-27-2012 at 9:07pm
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PETE, I saw in the thermostat thread you asked about a flush kit. What was that about? ------------- For thousands of years men have felt the irresistible urge to go to sea, and many of them died. Things got better after they invented boats. 1987 Ski Nautique |
Posted By: OverMyHead
Date Posted: June-27-2012 at 9:08pm
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Tim, it runs hotter with higher rpms. Specifically over 2500. ------------- For thousands of years men have felt the irresistible urge to go to sea, and many of them died. Things got better after they invented boats. 1987 Ski Nautique |
Posted By: 81nautique
Date Posted: June-27-2012 at 9:10pm
Pete's going to install a flush kit so he can wax his toilet bowl!! Inside joke ------------- You can’t change the wind but you can adjust your sails |
OverMyHead wrote:Posted By: OverMyHead
Date Posted: June-27-2012 at 9:51pm
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Ahhhhh! ------------- For thousands of years men have felt the irresistible urge to go to sea, and many of them died. Things got better after they invented boats. 1987 Ski Nautique |
Posted By: Bri892001
Date Posted: June-27-2012 at 10:00pm
| The flush kits are a common source of air leaks. There was another post where some kind of valve in it jammed (open?) and let air in. |
Posted By: 8122pbrainard
Date Posted: June-28-2012 at 8:26am
Alan, I used a new toilet bowl cleaner. It has teflon in it so it coats the bowl so nothing sticks!! Maybe I should try it on the Tique hull??  Dave, I mentioned the flush kit since they can be a source of sucking air on the suction side of the RWP. ------------- /diaries/details.asp?ID=1622" rel="nofollow - 54 Atom /diaries/details.asp?ID=2179" rel="nofollow - 77 Tique 64 X55 Dunphy Keep it original, Pete < |
Posted By: TRBenj
Date Posted: June-28-2012 at 11:07am
In that case, take a closer look at your impeller. Check for blockages too. If both check out, the RWP may be suspect. From what Ive experienced, an overheat at idle would indicate an air leak... which can be overcome by increased RPM's. Unless the leak gets worse with RPM (RWP seal). ------------- |