www.iFourWinns.com

Its a fresh water boat.

On a scale of 1 to 10 what would someone rate opening, cleaning and putting back risers.

Whats in there?

Anything to screw up?

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97 258 vista 7.4 VP/DP......... 2008 GMC Yukon XL Denali


96 sundowner 5.7 vp/sx (SOLD)

If you are talking about the exhaust elbows on top, you have to be careful of two things. Dont break off the bolts coming out.
Replace the bolts if they have any rust at all. You can get stainless ones at most hardware stores with stainless lock washers.
What ever you do, make darn sure you clean both side extremely well. If you leave one little piece of gasket or anything, you might hear a "Ting" when tightening the bolts. That will be your que to go find another Exhaust elbow and or manifold. These are cast iron and will not tollorate any thing less than a perfect mating surface.

As far as the temp goes, LouC had it right. What ever moron was telling you 180, was talking about cars.
At your 230 or 240, you are cooking the engine. You do that again, and you might be needing the whole thing. You can put cracks in the head inside the combustion chamber and go for awhile without knowing. Then when she blows, there won't be much left.

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1992 Baja 38 Special Twin 502 Mags

03 Stingray 3.0
88 261 Liberator 460 King Cobras
95 Bayliner 1850 3.0
77 Fiber Form 20ft 350/385hp
70 Wescraft 1800 SS 455 Jet

Lead, Follow, or get the Hell out of the Way!

What are the chances the gauge is not working properly?

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97 258 vista 7.4 VP/DP......... 2008 GMC Yukon XL Denali


96 sundowner 5.7 vp/sx (SOLD)

Just took off the thermostat housing and nothing in there?

If there is no thermostat in there shouldn't it be running cold all the time?





Apart from the 2 other things I circled there is nothing else that looks like a thermostat that I can see?

Something has to be restricting flow somewhere?

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97 258 vista 7.4 VP/DP......... 2008 GMC Yukon XL Denali


96 sundowner 5.7 vp/sx (SOLD)

Call Henry.... If he serviced it then he should know of any issues. Did it not overheat on the sea trial? Sounds like the guage is screwing with you or you have a blockage without a thermostat it should run cold.

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Marc, Kathlin & Nathalie


'89 Chaparral Laser 32

'93 Vista 245, 5.8L w/ King Cobra

Former Boats
'01 H260, 7.4 VP Duoprop
'98 H200, 5.0 GL w/VP SX drive

Wow! no thermo. How in the world would it maintain a temp without one?

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H210SS 6.2
F150 Platinum

With no thermostat, it's either the guage or the water pump. When you hook up the rabbit ears to the outdrive when out of water, to you get lots of water coming out of the exhaust? As in, as much as your hose is putting in. With a themostat in, it still comes out but reduced for the first minute or so. They are made to hold back water in the block and intake manifold, while by-passing the rest thru the headers.

If your water pump is not working, and they took out the thermostat, the water will most likely still not flow. They are set up on a balance type system and made to force it through the block.

I would check guages first, after you put a thermostat in it.

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1992 Baja 38 Special Twin 502 Mags

03 Stingray 3.0
88 261 Liberator 460 King Cobras
95 Bayliner 1850 3.0
77 Fiber Form 20ft 350/385hp
70 Wescraft 1800 SS 455 Jet

Lead, Follow, or get the Hell out of the Way!

Just a stupid question here but the water pump and sea water pump are the same right? If we are talking about the belt driven pump that I changed the impeller in? I had it in my hands and it seemed to be in working order not much on there to break or not work.

Unless there is another pump somewhere I have not looked at.

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97 258 vista 7.4 VP/DP......... 2008 GMC Yukon XL Denali


96 sundowner 5.7 vp/sx (SOLD)

There are 2 pumps; the one with the rubber impellor you have looked at feeds the whole engine system with raw water from outside the boat. From the top of the thermostat housing, this water is always fed directly to the exhaust manifolds/ risers. The other pump is fitted to the front of the block, like in a car engine, and it recirculates water over the engine/ inlet manifold. When the engine is cold and the thermostat is cold, no cold raw water gets into the recirculation system. When the engine is hot, the thermoastat opens and cold raw water finds it's way in. The thermostat maintains the correct inward flow of raw, cold water into the recirculating hot water to maintain a set temperature.

Externally, the recirculation pump looks just like an automotive one. Internally, they are different, with a bronze impeller and a stainless steel back plate. They usually fail due to leakage past the seals, water drips down out of the "weep" hole and gets sprayed everywhere.

Graham

I also just realized that the top hoses on the thermostat housing have been bypassed to my water heater.

Is that the way to go or not?

The yellow is going to the port manifold and the yellow runs to the water heater and then from the water heater to the starboard side manifold.

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97 258 vista 7.4 VP/DP......... 2008 GMC Yukon XL Denali


96 sundowner 5.7 vp/sx (SOLD)

I've not seen that one before, it doesn't sound right. I had another look at your third photo from yesterday; you can actually see the recirculating pump, it's the thing with the brass plug in it. The plug is usually cast iron and painted the same colour as the pump. That plug looks very, very new to me, suggesting a recent "modification" !

From what I have read, I believe that that plug is where the connection is usually made to the water heater, with a T price in the large diameter hose from that pump to the thermostat housing. I don't have a water heater on my boat, someone should be able to advise you about that with certainty. Maybe you're best asking that question in the Vista section.

Graham

Well guys I have finally fixed up everything after 2 weeks of troubleshooting.

My problem at the beginning was that the dash indicator showed the engine overheating and causing the engine to go into limp home mode

Here is a summary of the problem/solution.

Parts changed, Impeller, switch and added missing thermostat.

The source of the problem was that my engine is set up with dual senders circled in blue and red. the blue one is located right under the thermostat housing and the other circled in red is located in the water pump.

I verified all temps with infrared thermometer and the dash gauge was indicating the proper temp when the wire was hooked up to blue sender because the temperature of the blue sender was always around 220 degrees.

Now when I replaced the thermostat (that I tested in hot water and opened at around 140 degrees) the temperature of the risers and and manifolds were constant at 97 to 105 degrees.

The problem was resolved when I switched wires from blue sender to the red sender. The temperature finally corresponded with what was indicated on dash and at sender.

I still haven't figured out the reason why the temperature at the blue sender is much higher than all the other parts but the important thing is risers and manifolds are cool.

If someone could clarify that one for me it would end my quest LOL!!!

Now if anyone runs into trouble with either a faulty switch or sender and your engine goes into limp home mode you can disconnect the sender and switch and you engine will run fine. Keep in mind I had a thermal thermometer to make sure the engine really wasn't overheating before I went ahead and disconnected anything.

So in the end I changed a bunch of crap for nothing just cause of a wire being at the wrong place..............................

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97 258 vista 7.4 VP/DP......... 2008 GMC Yukon XL Denali


96 sundowner 5.7 vp/sx (SOLD)