www.iFourWinns.com

Does anyone know a good youtube video that does a step by step of winterizing the 3.0 OMC Cobra engine? I am pretty handy, and have decided to do my own winterizing starting this year. I understand about getting all the water OUT of the engine and drive, and getting anti-freeze in. Also, pulling plugs and fogging each cylinder, etc.

I am however a better visual learner, and LOVE seeing it first hand. I DO have a buddy that has an older MasterCraft that winterizes his own each year..he said he'd come over and show me how to do it, but I don't know if what he does with his Mastercraft, and what I would do with my 3.0 OMC would be the same.

And NO, I'm not winterizing yet, but planning for the fall.

Thanks
Dan

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1990 Four Winns 170 Freedom, 3.0 OMC Cobra 4 cyl.

fly I do it the easy way. No video but i'll try to explain. You'll need the following. Muffs of course, a 5-gallon bucket with a hose-bib added in at side/ bottom (drill the hole small so you can thread it in the bucket) a 'plastic garden-hose"Y" fitting . You'll have to sacrifice a piece of garden-hose and add a repair-end about 3ft. long. Fill the bucket with 4-gallons of anti-freeze. Set the bucket higher than the outdrive. Run the motor on straight water until it gets to operating temp. Switch the "Y"over to the bucket and suck all the anti-freeze out until it runs out the exhaust. Kill the motor.Done!

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Jimbo
Na. Ga.

2000 170 Horizon LS
4.3GL

This has been discussed many times and while some may do it this way there is a risk:
If the thermostat is a little sticky (common with raw water cooling) it may not open far enough to allow all of the raw water out of the engine. So you can wind up with either all water still in the engine or a weakened a/f & water mixture. Either one puts you at risk of a cracked block unless you:
1) take a sample from one of the drains in a paper cup and see if it freezes
2) drain the block before sucking in the a/f.

I tested this twice to see if the theory with the stat is valid:
1) tried this method the first time winterizing .... Pulled a block drain to check; what came out was dirty water
2) after manually draining and back filling with a/f, in the spring I ran the engine long enough to warm it up for a tune up. Checked the block drain; last fall's a/f was still in there...

I don't think some raw water cooled engines build enough heat running at idle on the water hose to fully open the stat; this method depends on the stat fully opening.

So if someone asks me how to winterize I always advise them to do the manual drain/probe the drain holes and then back fill with the best -100 marine antifreeze with corrosion inhibitors. The marina do use a suck through method but they know how to tell if the stat is fully open (so do I, using an IR temp gun) and they use a trough with muffs to re-circulate the AF to keep it hot enough to keep the stat open.

So doing a GM 3.0 4 cyl in line engine, about the easiest one there is to work on ever, you:

Put stabil in the gas tank
Run it on the water hose till warm
Change motor oil and filter
Run it again (check oil filter for leaks), remove the flame arrestor and fog the motor
Let it cool off
Remove all the drain plugs, 3.0 has on on the block and one on the manifold. Take a thin screwdriver and probe those holes make sure water comes out. Let it drain. Now remove the lower end of the big hose on the front of the engine that connects the thermo housing to the circulating pump, this will drain a lot of water. After you're done, take some gasket sealer like OMC gasket sealer and put it on the drain plug threads, replace the plugs. Replace the lower end of that hose. Disconnect the raw water intake hose at the thermo housing. Point it down in the bilge to drain the hose.
The Cobra drive has 3 water drain plugs in the pivot housing, you have to tilt it up to see all three. Remove them, rod the holes out with a stiff wire, tilt it down to drain. Then tilt up, put a bit of OMC gasket sealer on the threads, and replace them.
A/F is optional but it helps with corrosion control just like spraying Corrosion X on the trailer springs/ubolts does.
so to add:

Disconnect the big hose at the thermostat housing. Put a funnel in it. Then fill the hose till a/f comes out the thermostat neck. No need to remove 'stat. Re-connect hose.
Next, disconnect hose that feeds manifold at thermo housing. Fill manifold till a/f runs out the exhaust. Re-connect hose. Now disconnect the raw water intake hose that comes up from the transom to the thermo housing at the housing. Fill it with a/f till it runs out the water intakes. Re connect that hose.

Now your engine and manifold is full of -100 AF with corrosion inhibitors. This stuff does not freeze till -60 so no matter how cold it gets it will not slush up. The -50 slushes up at about 10* and the -60 at about 0 or so. We had 0 degrees here a few times this winter. I bet people that used the suck the AF up the drive method had some nasty surprises this spring.

Spray then engine esp the oil pan with Corrosion X or Boeshield T-9 corrosion inhibiting spray.

You should also change the gear oil in the drive (make sure if its a Cobra, that you do it the RIGHT way) and check for water in the gear oil. I take the drive off the next weekend to check the bellows and grease the gimble and u-joints and I reinstall it in the spring.

_________________
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

I've been doing the suck-it-in way for 20-years Lou. Never had a problem. But I live in the south. Boats are always inside a garage, not exposed to cold-winds. I suppose you would have to be a little more diligent up north.

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Jimbo
Na. Ga.

2000 170 Horizon LS
4.3GL

It's always a challenge to spray fogging oil down the carb, while you're watching the A/F level in the bucket you're sucking from & not run out of either!

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2011 Four Winns H180 SS.
Aussie built Mustang 2800.
SOLD - 1997 Four Winns Horizon RS

Yep for sure that's true. Our normal low temps are about 15-20* but this year it was extra cold and got to about zero. Actually if all you did is drain, that's fine too, because that's all you have to do to prevent freeze damage. The A/F is really for corrosion protection. The method I have above is what both OMC and Mercruiser have in their manuals, as far as how to use A/F. It would be interesting to see if you take a sample out of one of the engine drains and put it in a paper cup then put it in the freezer and see what happens.

_________________
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

Lou

YOU DA MAN..thank you for such a good writeup. I know I can do this with relative ease myself. So the drain plugs up on the 3.0 engine, are the two brass "fittings" on the port side of the engine correct? I've seen both of them. The one thing I didn't know about are the "3 drain plugs" on the pivot housing..where exactly are these? Up UNDER the outdrive?? what do they look like?

Lastly, on changing the oil in the engine..is there a "drain" of any type like a normal car engine has? Or how do I drain all the oil out of the engine? What oil and filter do I use to put back in?

Thanks
Dan

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1990 Four Winns 170 Freedom, 3.0 OMC Cobra 4 cyl.

For the engine and manifold drain plugs there will be something that looks like a T, brass in color,screwed into the block and in the manifold.
Tilt the drive up and look at the sides of the pivot housing; you will see 2 screw heads on the right side and one on the left side; those are the pivot housing drains.

I have pix from the original manual if you want I can try to post them to my Dropbox acct...
Changing the motor oil you need to buy a vacuum oil changer and it sucks the oil out of the dipstick tube after you warm up the engine for about 10min. I use Sierra marine oil filters and the Merc 25/40 marine oil. You can also use straight 30, 40, or 15w/40 heavy duty oil. Do not use car based multi grades like 5/30 or 10/30, they will thin out.
For the outdrive you can use the Merc High Performance gear lube, OMC Hi/Vis or Pennzoil Marine gear oil.

If you could find a shop manual it would really help you, the original OMC ones are much better than the aftermarket ones...

_________________
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

that would be great. Thanks

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1990 Four Winns 170 Freedom, 3.0 OMC Cobra 4 cyl.

OK hope you can see these pix.....

https://www.dropbox.com/s/4hum32lrkjn3s ... s.jpg?dl=0
PS #s 43 are the pivot housing drains on that side, but there's a better pic to follow...

https://www.dropbox.com/s/pnxkaf506wvau ... 1.jpg?dl=0

https://www.dropbox.com/s/mtmbog9eu3t6o ... 2.jpg?dl=0

if you plan on changing the gear oil, you must do it the right way, there is a dipstick on the top of the upper gear unit, there is a fill plug near the joint between the upper and lower gear units, and the drain is the lower most plug on the front of the lower gear housing. See better in my pics, but this is the procedure. Note: Most Cobras take about 2 qts of gearcase lube, some of the 4 cyl units take a little less. DO NOT FILL FROM THE BOTTOM DRAIN. It will leave you with an air bubble, under-filled drive and ruin the upper gears.
http://www.crowleymarine.com/support/te ... lling.html
Also the gaskets for the drain, fill and dipstick plugs should be changed each time. I get most of my stuff from a local Evinrude dealer, but Crowley Marine is very good.

there are more articles on OMC Cobra maintenance here on the Crowley website:

http://www.crowleymarine.com/support/tech_articles.html
Go to the OMC Cobra section, there are pix also of winterizing points that are better than some of mine....

Because its not that easy to find techs that really know these I've had to learn all this to keep it going. However, comparing the Cobra to the Alpha, there is no doubt in my mind that the Cobra was the superior product. In that:
Quieter, they do not whine like Alphas
When set up properly they shift better
Holds more gear oil, no need for a drive shower
Impeller much easier to replace
Bellows much easier to replace
ESA system does not kill engine while shifting (can stall it on an Alpha) OMC used the ESA module which lowers the RPM from 600-->400. Never had stalling problems with the OMC ESA system.
You need: a good shift cable, properly adjusted with the OMC tools. Its not rocket science and I have not felt any need to change to a different drive system as long as I can get parts.

Now no more discussion of winterizing, its August 18th and hot as hades out.

_________________
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

LOL....Lou...yeah, I have NO intention of talking anymore about winterizing. I HOPE to have a couple more months yet here in the upper midwest BEFORE I have to do this. BUT, I am one of those guys that likes to read and re-read and gather my supplies well in advance, so I am totally 100% ready for the job when the time comes.

I appreciate you taking the time to post all of this information. I KNOW ALL TO WELL about filling the outdrive the CORRECT way...I just had to replace the entire outdrive because the "SHOP" I took it to for oil changes, etc did NOT fill correctly, and I ruined the upper unit of my original drive. HENCE, the reason I want to do my OWN work now on my boat. That way I know it's done correctly.

Dan

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1990 Four Winns 170 Freedom, 3.0 OMC Cobra 4 cyl.

Great you will see that this especially on your engine is really not a hard job. You will have the satisfaction of knowing it was done right and if a cold snap is coming you don't have to panic because the mechanic doesn't have time to do your engine; in 15 min you'll have it drained....

_________________
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

Yeah...plus I always knew I was getting "ripped off" by taking my boat in every year for "winterization"....they charge me $225 each fall to winterize. I never really KNEW what was involved until I joined this forum. Now I know better.

I have read TWO differing school of thoughts however on changing the outdrive fluid. Over at Sterndrive.com....their instructions for the OMC is to fill through the lower unit bottom, hole, with the top fill hole screw of the LOWER unit removed..and pump in fluid just until you see it start to come out of the top hole of the lower unit. Then insert that upper holes screw plug....remove the pump from the lower hole, and put that screw plug back in. NOW, remove the upper screw plug again from the lower unit..and loosen the upper units dipstick...now start pumping in fluid into the lower units UPPER hole and measure on the dipstick, until it reaches the line on the stick, while it sets loosely in the hole.

Any thoughts on that method? I think THIS method MAY ensure the chance of an airpocket somewhere between the very bottom of the lower unit and the very top of the upper unit?????

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1990 Four Winns 170 Freedom, 3.0 OMC Cobra 4 cyl.

Lou..I think my next job will be the "Throttle" adjustment....I have only read enough about it right now, that I am kind of nervous about doing it...LOL

My boat shifts from neutral to forward and reverse OK....I just can't really feel any "definite" "Click" when I go from one to the other....to shift mine, it certainly isn't ONE finger, like so many talk about... Mine usually needs my thumb, index and middle finger on the shift/throttle level to maneuver easily from one to the other. once in forward or reverse, the throttle operates easily. Same as when I have it in "choke or idle setting" the lever moves quite freely.

Anyway, this will be a job for another time.

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1990 Four Winns 170 Freedom, 3.0 OMC Cobra 4 cyl.

I've always done it the 'official OMC ' way and never had a problem, so I keep doing it that way...it helps to slowly pump in the fluid with the top dipstick loosely sitting in the hole on the top cover which allows air to escape. I let it sit for a bit after the dipstick reads full and then re-check the next day, sometimes you have to add just a bit which you can add through the dipstick hole on top.
If it says it takes about 2 qts, buy three because you won't be able to pump in what's on the very bottom of the gear oil bottle...

As far as shifting, stiffness in shifting can come from a number of sources:
a worn, or corroded transom shift cable
worn remote control cable
crud built up behind the shifter bell crank in the pivot housing (I clean out this area and pack it with OMC/BRP triple guard grease)
a worn out remote control
If the stiffness is only noticed when shifting out of gear to neutral, then the ESA system (microswitches and module) need to be checked. What this does, is senses the pressure on the transom shift cable when you try to shift to neutral. The dog clutch tends to stay engaged and will not release unless the engine idle is lowered. So this lowers the idle from 600-400 for a second or 2 as you shift to neutral. You can actually see it on the tach as the needle dips briefly while shifting. This will not happen if you shift it on land running on the water hose because there is no pressure on the prop like in the water. If your ESA does not work, for sure shifting to Neutral will be stiff. It also helps if your idle speed is about 600 rpm with the boat in the water in gear. I have mine in good enough tune that it can idle at 550 rpm after warming up.

Doing shift cable on an OMC Cobra is not hard but is more difficult than other simple maintenance jobs. I did mine about 2 years ago because the adjustment on the remote cable changed a bit. It will actually shift with one finger (ie from FWD back to N, REV back to N). But this is because every year I have removed the drive, greased the shifter bell crank, lubed the shift linkage on the engine bracket, etc.

Has your mechanic been removing the drive each fall to do the maintenance checks? This should be done as part of winterization, because if the driveshaft bellows leaks, it will ruin the gimble bearing, u-joints and may cause the input shaft seal to leak gear oil.
So what I do is one weekend, I do the engine winterization, motor oil change and change the drive oil.
The next weekend, I pull the outdrive and do that maintenance. I have an outdrive cart and store it in the garage.
Then in the spring, I paint the drive and transom mount with anti fouling paint, reinstall it and tune up the engine and replace the fuel filter. Most of the time that's all that needs to be done, but this year I had a few other things to replace like the ESA switches and the ESA module.

_________________
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