Can I winterize my V8 stern-drive from the flush port - see picture-gctid828465

[Guest]

1988 5.7 OMC Cobra Sterndrive - See pictures - I want to winterize the engine without having to use muffs and lose 30% of my antifreeze. Can I simply pour the antifreeze into the flush port with the engine off by opening the valve to the engine and closing the valve to the drive. Then remove the impeller and reverse the valves to push antifreeze through the drive. Would this not work the same as running the engine and trying to suck the antifreeze through the muffs? I bought a 5 gallon water container to place on the swim platform to gravity feed the antifreeze to the muffs if I have to do it this way. The flush valves would be easier though! Thanks JR

[Norton_Rider]

Can you explain what you mean by flush port? I've had two boats with OMC Cobras and neither had a flush port.

If you decide to winterize by running antifreeze through the muffs, make sure that your boat's engine is fresh water cooled. If it is raw water cooled, you should winterize it by completely draining the water from the engine. The reason is that a raw water cooled engine will not get warm enough when running on the muffs. The thermostat won't open and the antifreeze will not run through the engine. The remaining water will freeze and may crack the block.

[Guest]

Tried to load the picture (jpeg file 1.5 MB) 5 times and it keeps saying File upload failed. This is a "T" set up: 3 - 2-way valves installed on the intake hose from the stern-drive to the engine. One is for a garden hose to the "T". The drive is shut off and the fresh water goes through the engine and out the exhaust through the drive. If you reverse it the water would go from the garden hose to the drive when the engine valve is off. I would remove the impeller and the thermostat to do this to allow the antifreeze to circulate throughout the engine. If someone can tell me why I cant load a picture this would help. Thanks JR

[Nauti_Mike]

No this will not work. Without the engine running and fully warmed up the t-stat will be closed and no antifreeze will circulate through the engine it will only go through the exhaust.

[dmcb]

Listen to the advise. Its golden.

Get a service manual and follow it exactly. Drain everything. Poke a wire or something in each hole to be sure it isn't clogged with sand.

Antifreeze can be used by professionals but they know exactly what they are doing.

You don't or you wouldn't be asking.

That is an expensive hunk of iron. Don't cut corners or try to invent a shortcut.

All winterizing is great in the fall. its the spring we get posts with water is pouring out of my engine as part of the message

I would urge you not to ask advise in winterizing on any forum. It is easy to forget something or not understand what you are told,

Service manuals will have pictures to help you,

Often overlooked on an OMC is there are drain plugs in the drive itself. They are hard to see if you don't know where to look. Personally I never had much water come out of them but a friend who was an OMC mechanic showed me one that was destroyed by not draining the drive.

.

Dou

[Nauti_Mike]

"dmcb" post=828498 wrote:
Listen to the advise. Its golden.

Get a service manual and follow it exactly. Drain everything. Poke a wire or something in each hole to be sure it isn't clogged with sand.

Antifreeze can be used by professionals but they know exactly what they are doing.

You don't or you wouldn't be asking.

That is an expensive hunk of iron. Don't cut corners or try to invent a shortcut.

All winterizing is great in the fall. its the spring we get posts with water is pouring out of my engine as part of the message

I would urge you not to ask advise in winterizing on any forum. It is easy to forget something or not understand what you are told,

Service manuals will have pictures to help you,

Often overlooked on an OMC is there are drain plugs in the drive itself. They are hard to see if you don't know where to look. Personally I never had much water come out of them but a friend who was an OMC mechanic showed me one that was destroyed by not draining the drive.

.

Dou

Well said Doug but apparently you need a service manual on how to spell your name. hmy:

[88fourwinns]

The best way to do it is proper manual draining poking holes and making sure the hoses drain. I would then put some OMC gasket sealer or Merc perfect seal on the threads and re install the plugs. I filled with antifreeze by backfilling through the hoses. It is optional to use AF, it is for corrosion protection not freeze protection. The drains for the drive are on the pivot housing, you have to tilt the drive up to see them. 2 on the stbd side one on port.

[dmcb]

Ha, I saw a letter missing on my name but didn't think it worthy of an edit.

One other thing I don't see posted about an OMC winterizing but told to me by my mechanic friend.

The drive should be removed each fall. Aside from greasing if the drive was installed and for some reason the gasket didn't seal (OMC had gasket sealer just for that purpose nicknamed "bear snot"}. water in there wouldn't cause a problem in use but would cause great harm if it froze.

Just a FUI.

Gaskets are cheap and easily available The bear snot is a soft non sticking sealing material used with the gasket. I still have some.

Doug

[88fourwinns]

Bear snot = OMC gasket sealer = Merc Perfect seal. When I install that gasket I put a good thick coat on each side of it and also on the mating surfaces of the drive and pivot housing. The main purpose of this gasket is to keep water out of the pocket in the pivot housing where the shifter bell crank resides. There are also 2 drain plugs on the outside of the pivot housing (starboard side) and the lower one is specifically there to drain that cavity if water gets in. When the gasket is installed as noted and that drain plug has its o ring intact (I put some gasket sealer on the threads) I have not had water in that area for years of salt water use. I fill that cavity with OMC triple guard grease just in case water ever did get in. The later model Cobras had a grease fitting added on the outside of the pivot housing to grease the bell crank .

PS there is drain plug on the port side that should also be removed and rodded out...

So as part of your winterizing you tilt the drive up and remove all 3 plugs (2 stbd, one port) . Rod out the holes with a thin screwdriver . Lower drive to let any water drain. Then tilt drive up re install all three plugs with gasket sealer on the threads. Make sure the o rings are intact.

[2850Bounty]

"dmcb" post=828498 wrote:


[size]6 wrote:
I would urge you not to ask advise in winterizing on any forum. It is easy to forget something or not understand what you are told,

Service manuals will have pictures to help you [/size]

Doug

[color]blue wrote:
Ditto Doug!

And DO NOT be tempted to use one of the winterizing kits that you will see advertised.

(Please read my October 2012 write-up on this topic.)

https://www.amazon.com/review/R3BD7X..._cr_pr_viewpnt

[/color]

[dmcb]

Yup. Its so easy to winterize as the mfg suggests.. There is no good reason to try another method.

If you think the mfg. instructions are not golden, just think of the liability if it were wrong.

Doug

[Norton_Rider]

"2850Bounty" post=828688 wrote:


[color]blue wrote:
Ditto Doug!

And DO NOT be tempted to use one of the winterizing kits that you will see advertised.

(Please read my October 2012 write-up on this topic.)

https://www.amazon.com/review/R3BD7X..._cr_pr_viewpnt

[/color]

As I've said in previous threads, you should not make a generalized statement. These winterizing kits work perfectly well on fresh water cooled engines. I winterized two fresh water cooled, OMC Cobra powered boats multiple times with a kit and never had any issues.

I agree that following the maintenance manual is the best way, but it is not the only way. The kit is particularly handy for people that use their boats year-round, as my wife and I do. The reason is that it is much easier and faster to winterize this way.

[dmcb]

Not familiar with the kit mentioned but failures have happened,

For example is the need for the t'stat to open covered. A necessary thing and someone not familiar with the need for that might get in trouble.

Another thought. A boat in the water in marginal freezing may survive where a boat out in the water at -50F like we can see here might have a problem.

Doug

[88fourwinns]

The key point is fresh water cooled (or closed cooling). With closed cooling those kits can be used, for sure, as long as the impeller will suck in the antifreeze. I'd probably use a bilge or livewell pump to pressurize the flow.

For raw water cooling, the problem is that if the block is not drained first, or the thermostat is not removed, the raw water will not completely exit the block because the thermostat may not open enough on the water hose on a cool fall day. So the only sure way is to follow the procedure in the manual, find all the drains, poke all holes to make sure they drain, and also drain any hoses that may hold water. As has been said many times before, you need a manual and you need to follow it. That's what I did 15 years ago when I learned to do mine and never had a problem. No short cuts.

[Norton_Rider]

"dmcb" post=828745 wrote:
Not familiar with the kit mentioned but failures have happened,

For example is the need for the t'stat to open covered. A necessary thing and someone not familiar with the need for that might get in trouble.

Another thought. A boat in the water in marginal freezing may survive where a boat out in the water at -50F like we can see here might have a problem.

Doug

"dmcb" post=828745 wrote:
Not familiar with the kit mentioned but failures have happened,

For example is the need for the t'stat to open covered. A necessary thing and someone not familiar with the need for that might get in trouble.

Another thought. A boat in the water in marginal freezing may survive where a boat out in the water at -50F like we can see here might have a problem.

Doug

Doug, the kit consists of a 5-gallon container with hoses and valves. The container is filled with RV antifreeze and connected to the muffs. The engine is started and the raw water pump sucks the coolant from the container. The antifreeze will go through the main heat exchanger, any auxiliary heat exchangers (oil, power steering fluid, etc), manifolds and risers. Then it will flow out with the exhaust. Thermostat opening or closing is not an issue with a fresh water cooled engine because the RV antifreeze flows through the raw water side and is not restricted by the thermostat. The fresh water side of the engine should already contain the appropriate concentration of engine antifreeze/coolant,; so this is not an issue.

The reason these kits should not be used with a raw water cooled engine is that the thermostat will usually not open when running on the muffs. This means that the antifreeze will never make its way to the whole engine. The remaining raw water will freeze and cause damage.

88fourwinns, I've always placed the container slightly higher than the sterndrive and I've never had any problems with the antifreeze getting sucked in.

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