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waldo
USA
73 Posts |
 Posted - 07/27/2008 : 6:48:59 PM
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Replaced impeller, therostat, water pump. What next on m/c trs drive outdrive woth sea pump,,, water intake located? Any other ideas??
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carvermitch
Canada
407 Posts |
Posted - 07/27/2008 : 7:06:56 PM
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Not a faulty sender unit is it or a sticky new thermostat. Also is the gauge OK but I guess you would have checked that. If it were a twin screw it could be the on the counter rotating engine impeller going in the wrong way - cant think of anything else unless a collapsed intake hose or blockage in the water jacket, rust or something.
Sorry thats all I can suggest.
Hope you find a solution.
Good luck
Regards
Paul
http://www.carvermariner.com |
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waldo
USA
73 Posts |
Posted - 07/27/2008 : 7:36:45 PM
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| Thanks on my 74 where is the intake ,under the outdrive? |
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BillMiller74344
USA
70 Posts |
Posted - 07/27/2008 : 8:06:11 PM
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On my 75 which has twin Fords, the water intake is on the outboard side of each Vdrive unit. There is a gate valve on the water inlet. The hose from that valve goes directly into the Vdrive cooler, out of the cooler is another hose that runs down the side of the end rearward to the inlet of the sea water pump.
wam |
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Rockmeister
USA
307 Posts |
Posted - 07/28/2008 : 11:59:43 PM
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Waldo, after the V-drive, the water goes into an oil cooler. There is a screen on the input side of the cooler. I dug quite a bit of debris out of the screen side of the cooler on mine.
Also, a lean engine condition or timing advanced/retarded too far can cause overheating.
Another possibility is the gate valve is broken internally and allowing the gate to be partially closed.
Does it want to overheat at idle, or just above idle?
'79 28' Mariner twin inboard V-drive.
SW Lake Erie: Maumee Bay & The Islands |
Edited by - Rockmeister on 07/29/2008 12:02:31 AM |
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mille73
USA
40 Posts |
Posted - 07/29/2008 : 08:42:06 AM
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If I'm reading this right you have outdrives not inboards. Correct. What impellor did you replace? The one in the outdrive for fresh water pickup. Never run without muffs the rubber impellor will be shot in seconds. Can you see exhaust water are you sure you are pumping OK.
Mille73 |
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waldo
USA
73 Posts |
Posted - 07/29/2008 : 10:04:57 AM
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| It is an I/O. Someone is looking at it and says it is not likey the intake but blovksge in the ??? cast iron jackets? might know more today |
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carvermitch
Canada
407 Posts |
Posted - 07/30/2008 : 07:38:40 AM
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Hi Waldo
Thats what I was suggesting in my previous message.
You more than likely have a build up of rust scale in the water jacket. It is quite common in older units. Sometimes they flake inside and cause partial blockages.
Hope thats all it is.
Good luck.
Paul
http://www.carvermariner.com |
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waldo
USA
73 Posts |
Posted - 07/30/2008 : 11:46:56 AM
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| I was told if they can not be cleaned out new ones cost 500each for a 351 ford. Does that sound right? |
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sea bitt
USA
63 Posts |
Posted - 08/01/2008 : 1:22:00 PM
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Is the price each engine or each side. If engine you are in the ballpark.
Bruce
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waldo
USA
73 Posts |
Posted - 08/01/2008 : 7:05:02 PM
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water jackets are clean now and running at 160. FYI a lever on the water intake hose next to the engine was moved so slightly during the work that is was ruuning at 170 closing it and it went back to 160.
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waldo
USA
73 Posts |
Posted - 08/26/2008 : 7:57:54 PM
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| Its still for sale, now down to 6k |
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Jerry
USA
64 Posts |
Posted - 10/21/2009 : 10:42:10 AM
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Greetings all,
I am adding to this post because of the subject and in hope that the solution will help those with inboards as well. I appologize that I haven't been here in a while, but I have been having a ton of boat problems and spending all my time trying to resolve them.
One problem that has gone as of yet unresolved is the engines overheating:
Let me give a little history: This past winter I repowered with Crusader Power Packs, which are 350 Chevy Long Blocks with Carbs and Ignition systems. They are "Vortec" engines and are just wonderful. The boat has performed so well since the change. However, I have been having overheating problems since the repower. The raw water pumps were rebuilt during the repower, the transmission oil coolers were replaced, all water hoses were replaced and the exchangers were "boiled out" and serviced by a radiator shop 2 years ago. The thermostates are new and the senders are new. The guages are 2 years old and an infrared temperature sensor confirms that the engines are in fact over heating approx 190 degrees at cruise. This problem exists on both motors, however the port motor (left rotation) heats the domestic hot water tank, thus it heats up slower and cools off slower.
I replumed the starboard engine to a half system, removing the exhaust manifolds from the inner (fresh water) loop. This helped, but after about 10 minutes of cruise running it rises up to about 175 degrees clearly above the 160 degree thermostat, however it holds steady there.
I came to the conclusion after making a ton of changes and tests that it must be the exchangers, so I replaced the port exchanger and to my surprise ... it did not make any change what so ever.
Thus, I am left with the only place that the problem could be is in the flow of raw water thru the system. My boat has "South Bay" straners on the bottom, which go thru a Ball Valve type shut off, which I have verified are in good and operable shape (all the way open) then the water goes forward to the V-Drives and I have opened and cleaned out the water jackets in the V-Drives. The water then goes aft to the Merc raw water pump. It then goes to the transmission oil cooler, then to the main exchanger and then out to the riser elbows. The Riser Elbows were switched from 3" to 4" during the repower and are new.
My current thinking is that the south bay strainers may be a problem, as well as the V-Drives. My thought at this point is to remove the South Bays and go to standard strainers and possibly install internal strainers, then to change the system to go straight to the pump, and feed the v-drives between the trans oil cooler and the exchanger. Also, since I have a 1985, I was thinking of going to an external oil cooler for the V-Drives, but in any case the water will go thru on the pressure side rather than the suction side.
My last thought is that the Vortec engines may just require too much cooling for this system design to handle, but I just can't believe that to be the case.
I know this is a lot of detail, but I would love to hear anyones oppinion or perspective on this. And as always, thanks so much for all your help on this.
Regards, Jerry |
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Rockmeister
USA
307 Posts |
Posted - 10/21/2009 : 3:23:43 PM
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I ran into somethinmg very close to this, ended up finding impeller parts in the thermostat housing.
Would check for any possible parts in any of the fittings.
Doubt the system doesn't have enough cooling capacity.
Does it do it at any speed/load including idle, or just under major load, etc?
Hope this helps!
79 28' Mariner twin inboard V-drive.
Western Lake Erie: Maumee Bay & The Islands |
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Jerry
USA
64 Posts |
Posted - 10/21/2009 : 9:44:24 PM
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Thanks Rock,
Yes, I have checked all the places that debris or parts would collect. However, the issue is with both motors. If I idle the motors at the dock they take a real long time 20 min or so before they overheat. Surpisingly the worst rpm is about 1200. But they come up pretty quick at cruise. If they are over heating and I increase throttle quickly ... they cool off then come right back up to temperature. The motor that I have switched the manifolds to raw water cooling even dips below thermostat temp before returning to high temp. |
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Rockmeister
USA
307 Posts |
Posted - 10/24/2009 : 2:39:21 PM
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Hmmmmmm...
That sounds more like a lean condition.
When you apply throttle, the accelerator pump sends a rich shot of fuel into the engine cooling it off.
Would do a close check of the spark plugs, see what they say.
The insulator of the plug should be about the tan color of cardboard.
If they are anywhere whiter or light grey the engine is getting too lean.
That will make it overheat and burn exhaust valves.
Rock : )
79 28' Mariner twin inboard V-drive.
Western Lake Erie: Maumee Bay & The Islands |
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Topic |
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Over heating
