1989 Ski Nautique 351w Hot
Printed From: CorrectCraftFan.com
Category: Repairs and Maintenance
Forum Name: Engine Repair
Forum Discription: Engine problems and solutions
URL: http://www.CorrectCraftFan.com/forum/forum_posts.asp?TID=48836
Printed Date: November-27-2024 at 5:01am
Topic: 1989 Ski Nautique 351w Hot
Posted By: Skinautiqueobsessed
Subject: 1989 Ski Nautique 351w Hot
Date Posted: June-10-2020 at 11:11pm
| I had my 89 ski nautique out for the first time this year and I noticed about 3 minutes in to running it at just idle, the temperature got to 220 and didn’t come back down. I kept going with about 1/4 throttle for 20 seconds and then I shut the engine off. I let it sit for a few minutes and then try to start it again. The engine tried to turn over but it wouldn’t. So I paddled back to the dock and loaded up. When I got home I took out all the spark plugs and cranked the engine over by hand. Water came out of most of the cylinders. I did not put a new RW impeller in this year. I used the best looking one that I had. I take it out over the winter. I did a compression check today on all cylinders and the highest consistent reading I got on a few of the cylinders was 180. The other cylinders were at 150. I did take the thermostat out last night and it did open up. What should I do next? TIA. Josh |
Replies:
Posted By: TRBenj
Date Posted: June-10-2020 at 11:16pm
| Drain then remove your exhaust manifolds, looking for signs of water in the runners as you disassemble. Positive compression test following an overheat + water in cylinders likely means exhaust is toast- but confirm. You’ll need to keep evacuating the water from the cylinders until it’s all out (and no longer draining in) ASAP. Else you risk cylinder damage. When did this happen? |
Posted By: Skinautiqueobsessed
Date Posted: June-10-2020 at 11:21pm
| It happened last Saturday evening. Any ideas on how the water got into the cylinders? I’ll start doing what you said and report back. |
Posted By: GottaSki
Date Posted: June-10-2020 at 11:51pm
|
Sounds to me like when it cooled down it pulled water up over both risers. PV=nRT ------------- "There is nothing, absolutely nothing, half so much worthwhile as messing around with boats...simply messing." River Rat to Mole |
Posted By: Skinautiqueobsessed
Date Posted: June-10-2020 at 11:56pm
| Just took off port side riser and everything looks ok. Now on to the starboard riser. |
Posted By: Skinautiqueobsessed
Date Posted: June-11-2020 at 12:13am
| Took off starboard riser and it looks fine as does the exhaust manifold and the muffler. Everything looks open to me. Do I need to take off the exhaust manifolds from the heads? |
Posted By: TRBenj
Date Posted: June-11-2020 at 8:26am
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Yes. You won’t learn anything removing the risers. I suspect cracked exhaust manifolds. Look for signs of water in the runners. Pressure test them either way. I’m not buying Tom’s theory, never seen that happen before. |
Posted By: Skinautiqueobsessed
Date Posted: June-11-2020 at 11:17am
| Sounds good, exhaust manifolds will be coming off tonight. When I looked down into the runners, the color was rusty looking right before it goes into the head. Not sure if this is normal or not? |
Posted By: Skinautiqueobsessed
Date Posted: June-11-2020 at 10:00pm
| I took both exhaust manifolds off, the bolts sure came out easy, I noticed they have anti seize on them. Anyhow, no noticeable cracks that I could see inside the manifolds. Definitely rusty and crusty inside of them though. I’m guessing the next step before I do anything else is to have the manifolds pressure tested? Thanks. |
Posted By: SNobsessed
Date Posted: June-12-2020 at 12:09am
|
Josh - You might want to pressure test the engine cooling circuit instead. You will have to plug all the holes except for 1 which you feed 15 PSI into. I still think intake manifold. You drained the exh manifolds last fall, correct? Unless they both froze-cracked, it is really unlikely they both failed simultaneously. Did you perhaps run the engine from the Timmy-T before the overheat happened? Maybe you left the valve open. ------------- “Beer is proof that God loves us and wants us to be happy.” Ben Franklin |
Posted By: Skinautiqueobsessed
Date Posted: June-12-2020 at 12:58am
| Chris - I’ll pressure test the cooling circuit this weekend. I did drain the exhaust manifolds and block last fall and put antifreeze in. I did not run the Timmy-T before we went out even though I wanted to. I am pretty sure the valve was shut. If for some reason the valve was open, could that have caused the overheat by not sucking in enough water? I did reuse the best raw water impeller you had. I wonder if I should have used a new one instead. |
Posted By: TRBenj
Date Posted: June-12-2020 at 7:25am
I think you’re discounting the likelihood... with an overheat that includes lack of cooling to the exh, cracking both manifolds is not uncommon. Have seen it 2 or 3 times. |
SNobsessed wrote:Posted By: KENO
Date Posted: June-12-2020 at 9:18am
I haven't seen any mention of whether there's water in the oil That's where the water ends up on an intake manifold leak. And besides it's good to know if there's water in the oil after something like this happens  As far as the cause of the overheat, I didn't see any mention or question about pump orientation after changing the impeller, |
Posted By: Skinautiqueobsessed
Date Posted: June-12-2020 at 11:29am
|
How do I pressure test the exhaust manifolds? Any pointers? I don’t think I have any water in the oil. I’ll check again tonight just to be sure. I changed the oil last fall before storage. I’m 100% positive I had the impeller going the right way. Probably should have used a new one though. |
Posted By: KENO
Date Posted: June-12-2020 at 11:41am
The real question though, is was the pump reinstalled in the right orientation so it would suck from the lake and push water through the cooling system? Yours should be like the left picture that says LH with the cam screw facing in towards the engine since this is a normal (LH)rotation in an 89 SN 
|
Posted By: Skinautiqueobsessed
Date Posted: June-12-2020 at 11:48am
| Keno - Yes, my impeller was installed like the picture on the left. |
Posted By: 8122pbrainard
Date Posted: June-12-2020 at 11:58am
Josh, You'll need to make a block off plate where the manifolds bolt up to the risers/elbows. Then it plugging up any extra threaded ports, adding water to another port and then a fitting to that port for regulated compressed air. Add the air and take a look inside the exhaust cavities for signs of water ------------- /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: Skinautiqueobsessed
Date Posted: June-12-2020 at 12:12pm
|
8122 - I tried a block of wood and clamps last night. I hooked my garden hose up to where the water enters the exhaust manifold. I had water squirting out from under the block of wood. I’m going to get a piece of steel, drill holes for the bolts, maybe make a new gasket, and then fill with water and air and see what happens. What about just dumping acetone into the exhaust manifold to test for leaks? Does that work? |
Posted By: SNobsessed
Date Posted: June-12-2020 at 4:16pm
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For an easy overnight test, just prop them upright, hook hoses a couple feet long to the inlet holes, raise hoses above top of manifold, & fill them. Leave them over night & look for water on floor in the AM. RWP had 'UP' marked on top, just FYI. Have you pulled impeller back out? No vanes missing? BTW, it doesn't matter which way the vanes are when you install impeller, they will self flip. ------------- “Beer is proof that God loves us and wants us to be happy.” Ben Franklin |
Posted By: KENO
Date Posted: June-12-2020 at 5:02pm
Glad to know the PO at least says the pump has been marked "UP" on top Just trying to see if he installed it right with the earlier questions and diagram. I'm not sure he answered whether the pump is installed right, since he keeps talking that the impeller is installed right
|
Posted By: Skinautiqueobsessed
Date Posted: June-12-2020 at 5:34pm
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Oil and oil level look great. The RWP is installed the correct way. I can read the word “UP”. The vanes on the impeller look great, none missing or burnt looking. Should I put acetone or just water in the exhaust manifolds? |
Posted By: GottaSki
Date Posted: June-12-2020 at 6:43pm
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If you didn't find two big holes I don't think you are going to find much. Superheated steam contracted and pulled water up over the risers. Google is awash with hydrolock after overheat stories. Seen it a couple times myself. ------------- "There is nothing, absolutely nothing, half so much worthwhile as messing around with boats...simply messing." River Rat to Mole |
Posted By: SNobsessed
Date Posted: June-12-2020 at 7:06pm
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It would take a lot of acetone. There is always the possibility you sucked up a plastic bag or such against the intake at the ramp. Regardless, after you get the exh manifolds sorted out & back on, run the 5 gal bucket RWP test to verify that it is working. ------------- “Beer is proof that God loves us and wants us to be happy.” Ben Franklin |
Posted By: Faceplant
Date Posted: June-12-2020 at 9:59pm
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I'm missing the point of what acetone has to do with leaky manifolds ? A little education please. ------------- Feels like I am hanging 10 but in reality - probably hanging 6. |
Posted By: Skinautiqueobsessed
Date Posted: June-12-2020 at 11:15pm
| Faceplant- I saw a guy on YouTube use it as a way to find the leaks in the exhaust manifold because it is supposed to by 4 times thinner than water. |
Posted By: Skinautiqueobsessed
Date Posted: June-13-2020 at 11:30am
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The exhaust manifolds survived the night, no leaks. I want to pressurize the cooling circuit on the engine to see if anything leaks and then I will run it in the driveway off of the 5 gallon bucket. |
Posted By: Faceplant
Date Posted: June-13-2020 at 10:08pm
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I am now officially edumacated . Thank You. ------------- Feels like I am hanging 10 but in reality - probably hanging 6. |
Posted By: Skinautiqueobsessed
Date Posted: June-14-2020 at 6:52pm
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I just pressurized the engine cooling circuit and I have no leaks into the cyclinders and the engine oil remained the same, I used my garden hose at full pressure for about an hour hooked into the port side thermostat housing with the two starboard side ports plugged and the thermostat removed. I rotated the engine over multiple times by hand with the spark plugs in and out. I’m going to pressurize the exhaust manifolds and if those check out I’m going to run the engine off of a 5 gallon bucket. |
Posted By: 8122pbrainard
Date Posted: June-14-2020 at 8:45pm
I'm confused. I thought you already did a check on the manifolds.
Was the first test without any pressure? ------------- /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: Skinautiqueobsessed
Date Posted: June-14-2020 at 10:18pm
|
8122 - the first test was done without pressure. I let water sit in them overnight. So far the pressure test of the exhaust manifolds look great - no leaks. Next up, run the boat off a 5 gallon bucket. I’ll report back how that goes. |
Posted By: lakedog55
Date Posted: June-15-2020 at 11:39am
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Could be thermostat. Not opening ------------- Lakedog55 |
Posted By: Skinautiqueobsessed
Date Posted: June-16-2020 at 11:30am
| I did test the thermostat and it does work. |
Posted By: Skinautiqueobsessed
Date Posted: August-06-2020 at 5:49pm
| I’m thinking it was a worn out impeller. I put a new one in and it stayed cool. |
Posted By: MrMcD
Date Posted: August-06-2020 at 6:40pm
|
You lucked out with your water pressure test. Most garden hose test at close to 60 psi. Normally the high pressure from a hose will blow out water pump gaskets. Auto systems never see more than 20 psi. Glad you have it running again. ------------- |