www.iFourWinns.com

Hi guys. My name is John and I am new to the forum, this is my first post. So here is my situation. I have an 89 sundowner with a 5.7 cobra. Up until today, it hasn't seen the water since 2008. So yesterday I changed the oil, hooked up the muffs, and she fired right up and I ran it for about 5 mins. No problems. Now the fun part.
Today I put in at the ramp, started right up and idled a couple hundred yards towards the end of no wake. Turned back to pick up the family at the dock and it started dying when not in gear. Trying to limp it back to the dock and noticed the temp guage nearly pegged out and some hazy smoke escaping from the side pockets. Shortly after this (still trying to get back to the dock) it started making a grinding noise and started to knock slightly.
This was enough for me so I shut her off and paddled onto the trailer.
Upon returning home it was completely cooled off so I decided to run some tests. Hooked up the muffs, started first turn of key, ran perfect. No noise except for what I think is the water pump. While running, I pulled the water pump hose off and it was bone dry in the hoses. I checked the impeller and it looked brand new. No signs of any heat.

So I guess my question is, will a new water pump fix my problem? I am an auto mechanic, just a little lost in the out drive world. Thanks for reading my book and I hope to hear back from you guys.

Yeah new impeller for sure.

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1981 Columbia 8.7
2015 Yamaha FZR - 87mph - sold
2006 Yamaha GP1300R - sold
2003 Chaparral 215 SSI - sold
2009 Stingray 195CS - sold
2000 Four Winns H180 - sold
1976 O'day Daysailer II - sold
Rick's Four Winns H180 Mods/Upgrade Thread

Ric he said the impeller looked new....

I would make sure you have no restrictions any of the intake portions of the raw water pump system.
and between the the pump and the engine waterpump.
did you check the thermostat? could be sticking

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"Changes In Latitudes, Changes In Attitudes "

1996 238 Vista dlx "Casper's Toy Too"
2006 5.0GXI w/closed cooling, DP-sm 1.95 drive
Previous boat:
1998 Sundowner 205

I just replaced my thermostat this weekend, I was having the same issue. I haven't been able to test it as of yet, but tonight sounds like a good time ti test it. Sorry to hijack your thread.

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1990 Four Winns Horizon 200
2005 GMC Sierra

When you say that, do you mean you actually had the impeller out and in your hand? 2 things that can cause the sudden temp spike and smoke, impeller or stuck T-Stat. Both easy to diagnose and fix.

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1996 205 Sundowner DLX
5.0FL Volvo SX Cobra
Tow Veh: 2012 Nissan Frontier Pro-4X

Can you confirm the impeller is spinning when the engine is running?

Long time OMC Cobra/OMC King Cobra/Volvo Penta owner here... there have been rare reports of the water pump in the outdrive stripping gears. Then you'd have no impeller movement, alas no water circ.
Just a "process of elimination" item to add to your list, thats all....

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1997 Four Winns Vista 278
T - 4.3l EFI
Kohler 4esz Genset
379 hours as of 8/8/21

The OMC specified raw water impeller test is to back the boat in the water. Remove the raw water intake hose at the Thermo housing. Hold the hose straight up whole someone starts the engine. You should see a good stre of water 2-4" high. If not you need to check the whole raw water supply system. It could be a blockage from old impeller pieces in the water intake line, bad thermostat or bad seals on the tube in the lower gear housing that transfers water from the lower to the upper gear unit.

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88 Four Winns 200 Horizon
4.3 OMC Cobra-4bbl
2002 Walker Bay 10/2012 Suzuki 2.5
2008 Walker Bay 8

1998 Jeep Grand Cherokee 4.0/Selectrac
2007 Jeep Grand Cherokee 5.7 Hemi/Quadradrive II

Looks new doesn't matter. Its been stuck in the same position for 5 years. Its trash.

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1981 Columbia 8.7
2015 Yamaha FZR - 87mph - sold
2006 Yamaha GP1300R - sold
2003 Chaparral 215 SSI - sold
2009 Stingray 195CS - sold
2000 Four Winns H180 - sold
1976 O'day Daysailer II - sold
Rick's Four Winns H180 Mods/Upgrade Thread

Yes I had the impeller out in my had. It was replaced for winterization. Still very flexible like a brand new one. I'm going to try a flush today. Is there a possibility of dobbers clogging up the line before the impeller?

Another question is: did I break anything during this event? It ran perfect on the muffs after cooling down

Well you're an auto mechanic, and it's just a standard chevy car engine. The typical dangers from overheating an engine including warped heads and or blown head gaskets. Also the rubber hoses that connect to the exhaust manifolds can melt.

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1981 Columbia 8.7
2015 Yamaha FZR - 87mph - sold
2006 Yamaha GP1300R - sold
2003 Chaparral 215 SSI - sold
2009 Stingray 195CS - sold
2000 Four Winns H180 - sold
1976 O'day Daysailer II - sold
Rick's Four Winns H180 Mods/Upgrade Thread

Like ric said, normal damage that would come from an overheated engine can occur. I had the same thing happen to me last season, luckily no damage to engine. The smoke was from the negative battery cable coating melting because it drooped low enough to come in contact with exhaust when my impeller failed.

New impeller and neg battery cable (tied up out of the way of exhaust), and all was well with no after effects to the engine.

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1996 205 Sundowner DLX
5.0FL Volvo SX Cobra
Tow Veh: 2012 Nissan Frontier Pro-4X

Impeller shaft is fine. Just checked that. What should I try next that I can do in the driveway?

Can't do it in the driveway, but Lou C has the best advice. Also, he is the resident OMC / Old Four Winns boat expert here IMO.

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1996 205 Sundowner DLX
5.0FL Volvo SX Cobra
Tow Veh: 2012 Nissan Frontier Pro-4X

Ok so I found this while flushing. Facing the motor, on the left hand side there is a hose that runs from the thermo housing back under the exhaust and connects to the back of the motor. It had a funnel like cup attached to it, but it was just hanging there. Is this my power steering cooler line? And is this my problem?