Newbie - What to service on 1989 OMC Cobra outdrives

[FrankyB]

I've recently purchased a 1989 Four Winns Vista 315 from a marine liquidator. The engines have less than 200 hours on them. The boat has not been in the water for 5 years. Part of my deal with the seller is the outdrives are to be fully serviced. They are Cobras and NOT King Cobras. I'm making my list to ensure they are fully addressed. What should I have on this list for servicing/replacement? Thx!

 

[Lou C]

The drives should be removed and the U joint bellows checked and replaced if there is any sign of cracking or water in the bellows. The gimble bearing should be checked for smooth operation and replaced it its rough when you turn it. The U joints should also be checked for looseness and corrosion. The driveshaft splines should be sharp and not rounded off. Take a flashlight and look inside to see if the inner splines in the coupler are not worn; they should be squared off. The transom shift cable should be checked for drag and proper adjustment. The drives should have the oil changed and be pressure checked, make sure there are no gear oil leaks. The raw water impellers should be replaced.
The gimble bearing and u joints should be greased with marine wheel bearing grease and the driveshaft splines should be greased with OMC triple guard grease. Before re installing the drives engine alignment should be checked and adjusted if needed.

When the drives are reinstalled they should be checked for proper shifting and make sure that the ESA system works. The drives should shift into gear without grinding; there may be a "thunk" when they shift into gear but no grinding.
When shifting on the water they should shift easily in and out of gear and they must not jump out if gear; that will ruin the clutch dog and lower gears.
Idle should be 500-600 in the water in fwd gear. When you shift from fwd or rev to neutral you should feel the ESA system briefly lower the idle r p m from 500-600 down to about 400. It should not stall when shifting to neutral nor should it take a lot of effort to shift to neutral.

 

[Gilded_Splinters]

As the other member with twin Cobras, I can say that Lou has it covered, but there is one more thing to look at while the drives are off:

There is a plastic tube running between the zerk fitting on starboard side of the drive and the gimble bearing that is often broken or disconnected. You'll want to repair these if they're not intact as they are the only means of greasing the bearing seasonally.

It sounds like a lot, and it is, but don't short cut or you'll regret it.

 

[HT32BSX115]

What should I have on this list for servicing/replacement? Thx!

MAKE ABSOLUTELY SURE that the servicing mechanic knows how to refill those drives with new gear oil!!


After draining, ensure that they are filled correctly via the FILL port IAW the correct OMC service instruction or you will be buying rebuilt drives.

Cheers,


Rick

 

[FrankyB]

Thank you gents! Couple of questions:
Lou - what is ESA that you reference?
Gilded - if the tube is broken, where can I get a replacement or, is this jus standard tubing?
Rick - you mention using the fill port IAW. Where is that? Do you have a picture?

I'm excited to be a member of this forum as I can already see the value (and hopefully the friendships) that come from it! I'll be posting a lot under the repair and restoration.

Frank

 

[HT32BSX115]

Thank you gents! Couple of questions:
Lou - what is ESA that you reference?
Gilded - if the tube is broken, where can I get a replacement or, is this jus standard tubing?
Rick - you mention using the fill port IAW. Where is that? Do you have a picture?

I'm excited to be a member of this forum as I can already see the value (and hopefully the friendships) that come from it! I'll be posting a lot under the repair and restoration.

Frank

Howdy Frank!

Welcome Aboard by the way!........ if no has said that........

There's a drain "port" at the bottom of each drive and another about halfway up the side (this is the "fill" port) . Someone should see this and post a picture for you.

Mercruiser drives (and some others) are filled from the bottom.

The Dog-clutch Cobras are filled from the "Fill" port to prevent/reduce the bubble that is trapped when filling from the bottom. Filling from the bottom causes that bubble to eventually rise to the top uncovering the gears at the top. Uncovering the gears which run submerged in oil quickly destroys them.

You'll probably want to do a little reading on the Cobra and how the ESA works.

http://www.hastings.org/~stuart/cobra/

Cheers,

Rick

 

[jerryjerry05]

The others have given a lot of good info.
​This will help too.
Get a FACTORY manual.
Clymer and Seloc sell a manual and there is some good info in there.
Buy one of them too.
But a factory manual is the best.

On the transom assy. is a bellows, under the bellows is the shift assy.
The assy has a part called the bellcrank.
It gets corroded and can lock up or cause hard shifting.
Just make sure it's lubed.


Good luck with your boat.
Location? You might be close to someone who can help.

 

[Lou C]

The Cobra ESA is an electronic module that lowers your normal idle speed from 600 rpm or so down to about 450 or so. This is needed to allow the clutch doge to release the fwd or rev gear so the drive will shift to neutral. It is triggered by micro switches on the engine shift bracket that act in response to pressure on the transom shift cable when you try to shift to neutral. This system must work for proper and safe operation of the shift system. When it is all set up properly it works great.

 

[FrankyB]

Thank you Lou! Is this something that typically goes bad on these units? And, if so, is this a sourceable part?
Frank

 

[FrankyB]

JerryJerry: Thanks for the info. I'm out on ebay this morning looking for manuals. What kind of lube is used on the Bell crank? BTW - I'm located on Lake Norman in Charlotte NC.
Frank

 

[FrankyB]

Rick - thanks for the Link(s)......I'm learning a lot from them!

 

[FrankyB]

While trolling through Ebay, I came across seal kits available for the upper and lower units. Given my boat has been out of the water 5years, is this something else that should be done? If so, how laborious is this (ball park)?

 

[Lou C]

The ESA is not trouble some in general but I just replaced my 28 year old switches and the original module stopped working this summer. But that shows that the the original components were well made and yes you can still get the parts from BRP. What usually causes trouble is a sticky defective transom shift cable and water getting into the cavity where the bell crank is in the pivot housing and that causes stiff shifting. If it passes the pressure test Id leave the seals alone. I do replace the fiber (plastic) gaskets on the drain and fill plugs every time I change the gear oil.
The things to pay close attention to:
Drive shaft bellows
Bell crank in the pivot housing
Raw water impeller
Gimble bearing&u joints
Transom shift cable
ESA system

On my boat all this gets checked every season.
I have found that with proper maintenance the Cobra drives will last a very long time and shift well. In some ways they are easier at service than comparable Mercruisers.
The main things that may cause issues from 5 years of non use are the raw water impellers; I would replace these even before starting it because you don't want the vanes to break off and clog water passages. Use original equipment impeller kits from BRP. If you have an Evinrude dealer near by they can order original parts for you...

To lube the bell crank I use OMC/Bombardier triple guard grease (Evinrude blue grease) it is the best water proof grease I have found. I pack the whole cavity for the bell crank with it.
Other tips:
On the pivot housing there are 2 water drain plugs on the right side as you face it from the rear. The lower one is for that cavity. Put some OMC gasket sealer on the threads and rubber o ring of that plug. When re installing the drive coat the pivot to drive gasket generously with the same gasket sealer, it keeps water out of there.

 

[HT32BSX115]

While trolling through Ebay, I came across seal kits available for the upper and lower units. Given my boat has been out of the water 5years, is this something else that should be done? If so, how laborious is this (ball park)?

Frank, You don't have to reseal a Cobra unless it's leaking. (either oil leaking out or water getting in)

Like Lou mentioned, the ESA doesn't usually doesn't fail. You can test them with an engine running by actuating the system manually. It should cause each engine to "lope" (The ESA actually "pulses" the ignition to produce the torque pulses sufficient to separate the "dogs")

That torque holding those dogs together is only present when the boat is in the water (I.E. there's a [water] load on the prop) This means if you try to test it by shifting the drive on the trailer, the ESA will not actuate. (there's no load on the prop when it's spinning in air!)

Also, the ESA(s) should only actuate when you are coming out of gear. (It's not needed to place the drive in gear FWD/REV) AND if it does actuate when going into gear, your lower shift cable or shift mechanism in the drive may be binding.

proper adjustment is EVERYTHING with a dog-clutch Cobra. Adjusted properly, they shift into and out of gear reliably. Adjusted wrong, and you have the risk of permanent damage.

None of us here want to scare you ..........but basically 2 things will "kill" a Cobra (aside from driving it into the rocks!) ...............A maladjusted shift system AND filling the drive wrong....(with oil) The former will damage the shift dogs in short order and the latter will destroy it with only one trip around the lake.

A Lot of times we get people here asking questions after the damage is done! It appears you are here before all this can happen!!:thumb::thumb:

 

[FrankyB]

. Use original equipment impeller kits from BRP. If you have an Evinrude dealer near by they can order original parts for you...

To lube the bell crank I use OMC/Bombardier triple guard grease (Evinrude blue grease) it is the best water proof grease I have found. I pack the whole cavity for the bell crank with it.
Other tips:
On the pivot housing there are 2 water drain plugs on the right side as you face it from the rear. The lower one is for that cavity. Put some OMC gasket sealer on the threads and rubber o ring of that plug. When re installing the drive coat the pivot to drive gasket generously with the same gasket sealer, it keeps water out of there.

Who is "BRP"?

Where would I be able to find the p/n and purchase the "O ring" and gasket that you reference?

Thanks guys!

 

[FrankyB]

Lastly - water pumps: Should the water pumps be changed out along with the impellers? I know in cars, its normally suggested that water pumps be changed when changing the timing belts. What is the rule when it comes to marine?

 

[HT32BSX115]

You have 2 water "pumps" for each engine/drive. The raw water pump in the drive and the circulating pump on the engine.

The raw water pump should probably be inspected every couple of years or so and replaced as needed. The circulating pump on the engine is nearly identical to a water pump on your truck EXCEPT it's usually got stainless steel backing/cover to help prevent corrosion.

If you have closed cooling you can use a standard automotive pump. If you have open cooling(and you're operating in salt) , you should use a "marine" pump.

My last circulating pump on my previously installed 460 was there for at least 15 years(boat operated in NON-salt water) .

My last boat had a GM 230cu-in inline-6 (Mercruiser 150) ..........It was a 66 model. I sold it in 2005. (39 years) it had the original circulating pump on it..............and boat only operated in salt water once or twice in those 39 years

BRP=Bombardier Recreational Products Inc

Evinrude/Johnson


You can get part numbers here---> http://epc.brp.com/SiteMods/BRP_Public/BRP_Public_Login.aspx?ReturnUrl=/Index.aspx

Just follow the prompts. (You can leave the email field blank)

 

[Lou C]

BRP bought the assets of OMC after they went bankrupt in 2000. The circulating pumps last a long time even in salt water. My OE one I replaced after 22 years with a Sierra Marine pump. When the bearing starts to get noisy or you see water leaking from the weep hole it's time for a new one.