Winterize F26 351 water leak?

[wesm]

Hi in my 3rd year of ownership of the boat was looking to winterize myself this year. I had trouble last time out and had to be towed in. Took on water and was not sure why. The engine ran hot then rough and ultimately stopped. Was able to started agin in the water but thought the engine was the reason we were taking on water. No water in either the velvet drive or the engine oil. No oil in the water in the bilge. Discovered next day a blown 3" exhaust hose. So replaced it. Tried to discover why engine died and checked points and they were shot. I replaced rotor, cap, points, and plugs. RV12YC (what should the point set be and the plug gap?). Engine fires almost as thought points or plugs are off but does not run. I trailered the boat from Minnesota to Calgary Alberta. At any rate I decided to pump rv antifreeze (cold cranking the engine) into the system and noted that the antifreeze came out somewhere underneath. So could it be 1.water pump? (at least automotive water pumps could leak like as sieve when shot) 2. frost plug, 3. crack in water jacket.

Ideas to isolate would be much appreciated.

Thanks

[aweimer]

Here is the spec sheet for the engine. Has all the details on the timing and points you need.

[wesm]

Thanks for the specs, I have another and wonder what the dif is between the plugs the one I installed is champion as well. It is probably not huge but curious. Here is the data I found elsewhere on the plugs. I ask because I had a mechanic tell me on on an 81 chev 350 a particular plug sat a little deeper in the combustion chamber and therefor fuller comustion burn.

Spark Plug: (18MM) AC-C83T or Champion F-10 ...................(14MM) Champion RBL-11Y (RV12YC) Plug Gap: .030

[jon_e_quest]

Thanks for the specs, I have another and wonder what the dif is between the plugs the one I installed is champion as well. It is probably not huge but curious. Here is the data I found elsewhere on the plugs. I ask because I had a mechanic tell me on on an 81 chev 350 a particular plug sat a little deeper in the combustion chamber and therefor fuller comustion burn.

Spark Plug: (18MM) AC-C83T or Champion F-10 ...................(14MM) Champion RBL-11Y (RV12YC) Plug Gap: .030

Your engine's heads are tapped for either 18mm (13/16") or 14mm (5/8") plugs. The size refers to the socket needed to remove/install them and Mercruiser is suggesting the aforementioned brands. These can be used to cross-reference other brands of your choosing. (FYI: Type RBL-11Y is now called RV12YC)

[wesm]

Thanks for the clarification on the plugs. Today I went out to just push RV antifreeze through a pump to figure out the leak issue. Did not cold crank. There was leaking by the raw water pump. I also heard an gurgling that sounded further back toward the vdrive. I used some mirrors but could not see where the water was coming from. It was getting dark so I will check tomorrow when there is more light. I wonder if someone has a general idea of where the frost plugs are on the 351. I believe the motor is right hand so in reference to the plugs what spark plugs would the frost plug(s) be closest to.? The water appears to come from the 5, 6, 7, 8 plug side of the motor.

Thanks in advance.

Wes M.

[wesm]

I discovered primary the leak issue. The marina that I kept the boat at the previous two winters had failed to tighten the clamp on the transmission cooler. I pulled off the deck to get a peek at the motor and the water cooler hose was off the tranny cooler.

Pretty frustrated as this year we had planned a weekend out on Lake of the Woods and part way out (about 30 minutes into the trip)to an island we started to take on water. I now suspect the issue that caused the 3" hose break was the result of the hot air coming off the engine because the cooling system was compromised.

When we put the boat this year the marina owner realized he had failed to put the hose fromthe sea cock back on from the winterizing of last fall. The year before they had put RV antifreeze into the system. This past winter they must have just drained the system. We caught that sea cock hose right away upon the boat launch, but the water cooler hose didn't show until I had pushed the engine up over 2200 RPM. I had initially thought the large hose failure was due to the hose being old. Now I believe it was tied to the tranny cooler hose coming off. When I place the hose back on again and went to tighten the clamp I had to tighten the clamp over a half an inch.

Worst of it was I paid him to tow me back.

I'm not clear as of yet the tranny condition other than the fact the fluid looks burnt.

Wes