www.iFourWinns.com

Took the boat out a couple of weeks ago after a lay up of about three weeks, all was normal except for intermitent beeping when the boat was put on the plane, this lasted fairly much the whole trip (1/2 hr) to the beach where we stopped for the day.
Heading back we idled out through moored boats, went to put the boat on the plane, there was one loud continous beep, put the control to neutral and noticed, the temp gauge was up around 200 deg, shut the engine down.
Started the engine again and attempted to idle back to the ramp but temp just kept rising to around 200 deg but did not sound alarm, thought it was best to get towed back to the ramp.
Towed the boat home put it on the flushing muffs noticed it was not sucking as much water as it usually does.
Took the boat to the mechanic, he told me the intemitent beeping was failure of the temp sender, as it was clogged with sort of rusty metal flakes even grit, so this was renewed as well as the thermostat that was suspected to be filled with grit and not operating properly to cause overheating, he also ran his dionostic equipment and found nothing except the temp sending faults. He ran the boat on flushing muffs and reported normal, but he still was not 100% sure it was fixed and told me to put it on the muffs before i took it out and then take to the water, if it still overheats he would have to bring dionostic equipment and test it in the water.
Anyway yesterday put the muffs on the boat and still seemed that it was not sucking the normal amount of water, but the admiral insisted that we should launch and give it a proper test, so in to water the boat went, by the time the admiral had parked the truck the temp had started to rise, and by the time we had gone 50 m on slight throttle the alarm had sounded, so i shut the engine down waited several miutes and then returned to the ramp.
Impellor and new housing where done August last year, risers and manifolds have not been done, but the mechanic said that these run gradually hotter over time and dont sudenly start to overheat.....Please help!

Regards Scott

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2005 Four Winns Sundowner (Sold)
350 MAG B1

It shouldn't be the impeller, but if the sender & thermostat have already been replaced I'd open up the impeller housing and see what it looks like.

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Mike
2005 Four Winns 230/240
VP 5.7GXi/DP
1998 F-150 XLT
Boat Pic

I'm with Mike sounds like the impeller to me. Despite the fact that it was recently replaced.

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2008 Horizon 260 VP 8.1 Gi

... even if the impeller was recently replaced, did it fail before??? If so, did all the pieces get removed from the cooling system? Start by replacing the impeller and move from there. Could be a blockage, even if the impeller is good.

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Walt B
"Debt-Charged"
Black '07 H210SS
6.2L Bravo One turning a 21P HIFive
Wakeboard Tower with Perfect Pass Stargazer version
Missouri River; Kansas City, Mo.

When you run the engine at home on the muffs, Are you covering up the low water pick up holes at the nose of the lower unit housing? (I use gray duct tape) Also are you using big enough, And tight enough ear muffs to cover the holes on the side of the lower unit with the water pressure all the way up?

Also you should lower the drive first then align the ear muffs holes to the center of the holes on the drive, Then hook up the water hose, Then cover the low water pick up with tape, Then turn the water all the way up slowly so the air in the hose does not move the muffs off center of the holes.

If you do not set it up like this you could damage the impeller while running the engine at home (IMO).

Or do you have the low water pick up flusher?

Thanks for the replys guys, looks like we will have to get to the impeller, the impeller has never been replaced due to failure,(very difficult Job on this model) and there has not been any engine problems in five years.

I have noticed a difference when on the muffs; That when it is nomal, i turn the hose on half way and there is water spurting from the sides of the muffs(with saltaway mixer), then start the engine it sucks a little in, i turn the hose on fully and as i the thermostat opens there is no water spurting from the sides of the muffs, i also block the bottom pick up with duct tape.
The condition that the boat is in now with it sucking a bit of water with a slight change of intake when the thermostat open, but the water was still spurting from the sides of the muffs, and not be totally sucked in as when nomal.

I do not know why when heading out on the day we had the overheating and sensor problem; we drove half an hour with the temp sending alarm, and then had an overheat. One would think that the sensor would say malfunction, replace that and all would be good, but then on the same day an overheat which seems to be constant, is it a coincidence or does anybody know a logical reason for this?

Regards Scott

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2005 Four Winns Sundowner (Sold)
350 MAG B1

Scott, I'm confused. Your OP said the impeller was replaced in August, but then your last post says it has never been changed due to failure.

Do you mean that the impeller was replaced as part of routine maintenance last year rather than failure? If so, I'm with you but I could also read this differently to say that an attempt was made to change the impeller but that attempt failed.

Also, I'm not one to put a whole lot of stock in how things appear outside the boat on the muffs. I'd go with the performance in the water above anything else.

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Paul
2007 Four Winns Horizon 220
Mercruiser 350 Mag MPI w/ Bravo III Drive
2004 Ford Explorer Limited (V8-AWD)
Pomme de Terre Lake (Southwest Missouri)

Yes, the impeller was replaced during routine maintainance, and an on water test was given after the replacement of the thermostat and temp sender, still overheating.

Just courious to know why the sensor failed and had the overheat on the same day?

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2005 Four Winns Sundowner (Sold)
350 MAG B1

I returned to the mechanic. This time he suggested inspecting the water pump housing and the impeller, he also removed and inspected the risers, flow tested and thought that they looked alright, so reinstalled them. He replaced the housing on the water pump as it was scored and the impeller . Again we took the boat out to see if the problem was fixed but the boat is still running hot on idle. Each time we reved the motor (about 2000rpm)the temperature seems to reduce almost to normal operating temperature. On the plane it appears to be running only slightly above its normal temperature but it feels like it is running a bit rough. All through this, the amount of water that is being taken in when on the muffs seems reduced. We are suspecting a blockage of some type but don't really know how to proceed and have already spent a fair bit trying to work it out. Any ideas or help would be much appreciated.
Scott.

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2005 Four Winns Sundowner (Sold)
350 MAG B1

Hmm, does sound like a blockage. Something sucked into the drive?

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Mike
2005 Four Winns 230/240
VP 5.7GXi/DP
1998 F-150 XLT
Boat Pic

Hi Mike,
The impeller was fairly intact when it was removed (no missing pieces) had seemed to just lost a bit of "memory" do you think the blockage would be in the hose between the leg intake and impeller pump housing as anything that got to the impeller and not destroyed it would have got chopped up?

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2005 Four Winns Sundowner (Sold)
350 MAG B1

Like on the VP set up, inline between the transom and raw water pump I believe there's a power steering fluid cooler. Probably at the back of the engine somewhere. I'd have a look in there. If that's clear, maybe back flush to the outdrive to get an idea if the blockage is in the outdrive itself.

Graham

Not familar with the B1 drive but most outdrives have a water tube that goes from the water intakes up through the upper unit to the water intake hose to the impeller...these tubes usually have seals on them and can fail....
Most manufacturers have a test in the water for the impeller...I'd want the mechanic to test it in the water to make sure the impeller is sucking up an adequate volume of water. For my old OMC you have to disconnect the raw water intake hose temporarily and start the engine for a minute and hold the hose up....and then watch to see how high the column of water that is pumped out is...You can't test an impeller on the muffs...the water pressure from the hose will mask problems...

I am in salt water (moored boat) and we get barnacles growing in the water intakes...so every year I remove the old impeller from the rear of the upper gear housing (OMC Cobra) and break up the barnacles with a really small scewdriver or pic and then flush em out with the muffs when the drive is off the boat on my work stand...any restriction in the water intakes can cause a similar problem...

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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