Where should I go from here? (Outdrive question)

Hello all,
I am looking for some input regarding service/ evaluation of an outdrive unit. I have years of mechanical experience working on many different things, but little experience with marine engines. Information and details below. I looked through the forum but could not find anything that matches my situation closely enough so I thought I would ask to see if anyone might be able to save me some time and frustration.
Make: Starcraft
Model: Islander 221 v
Engine: GMC 4.3L V6
Outdrive: OMC Cobra Standard
Year: 1988
I recently purchased this boat from an estate sale. Unfortunately, the vessel did not come with any information about what service had been done recently, or what problems it might be having. The engine itself is in great condition. It looks to have been recently serviced as it is very clean and many of the stopnuts look fresh. The outdrive was detached from the vessel and placed on the deck of the boat. I cannot discern with certainty whether the outdrive had been removed for basic maintenance and replacement of bellows, or if there was some problem the previous owner was trying to fix. My logic leads me to believe that the previous owner was doing routine maintenance as the engine had clearly been serviced recently, and the project must have simply become arrested halfway to completion.
I am considering finishing replacement of bellows and standard lubrication etc. and all other standard maintenance which should be done while the outdrive is detached, but before I do I had a few questions which I am curious if anyone in the community might be willing to help me out by sharing any opinions or information they might have:

1. Is there any way that I can test the quality of the outdrive, or check for any problems that it might have before I re-install the outdrive on the vessel? Notes on this below:
   1. I do not know how long this outdrive has been detached for.
   2. The upper cover had been removed, and the outdrive has been drained of oil. Should I be at all worried about this having generated internal issues for the outdrive? At a glance I do not see any rust developing under the cover.
   3. some rust began to develop on the drive shaft (photo included). Should I worry about this or shall I simply remove it with some extra fine sand paper?
   4. It looks like the previous owner spray painted over the Zinc Anodes. Should I replace those, or try to sand off the paint?
   5. This vessel came from an area of the country where I feel it is highly unlikely it has ever seen saltwater.
2. Are there any other components of the drive system that should/can be tested while the outdrive is already removed?

Big picture: I would like to determine whether this unit can be used again, or if I should replace this with a new or re-built unit. Cost is a large factor for me so I am looking to pursue the most affordable option. If this outdrive can be salvaged I feel it will be the less expensive option.

I can easily upload more photos, and provide more information if needed.

Thanks in advance for your time!

You asked "where should I go from here?"

If it was me, and if I really loved this boat, and if I planned to use and keep it for years........ I would sell that Cobra drive and replace it with a V/P SX and the installation kit.
No more ESA, no more Dog Clutch, no more lower shift cable issues.



Now I say this with humor...... if you are a glutton for punishment, keep the Cobra.



.

they can sit without oil and be fine. You can shift the drive by hand and rotate the driveshaft and see if it rotates and shifts. The, I would just put everything back together and try it.

If it fails, Getting the drive rebuilt won't be crazy expensive - maybe $1500 to $2500 depends on who in your area works on OMC Cobras. In some areas it's hard to find service. In many areas there are a lot of techs who still like working on them.

SEI makes a kit to convert to a Mercruiser outdrive which is the most common type around. it's around $3K with a brand new drive and 3 years warranty.

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hystat said:

If it fails, Getting the drive rebuilt won't be crazy expensive - maybe $1500 to $2500 depends on who in your area works on OMC Cobras. In some areas it's hard to find service. In many areas there are a lot of techs who still like working on them.
Good point. Find out if anyone in your area works on the OMC Cobra.

SEI makes a kit to convert to a Mercruiser outdrive which is the most common type around. it's around $3K with a brand new drive and 3 years warranty.
All due respect.... going from a Cobra to an SEI Alpha "wanna-be", is a step in the wrong direction.
It begs the question: "why trade one Dog Clutch drive for another Dog Clutch drive?"

For a few bucks more, you can pick up an SX (in the correct ratio) and the installation kit, and end up with a smooth shifting, trouble-free, Cone Clutch drive.


By the end of 1993, OMC had gone belly up!
By 1994, it had been purchased by Volvo Penta.
The Dog Clutch Cobra went bye-bye and was replaced with the Volvo Penta SX and the DP-S cone clutch drives.

Click to expand...

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Thanks for your replies Gentlemen!

Ricardo, Thanks for your idea to upgrade to the SX! I had not considered that! I will definitely consider that option in the future as my finances allow. For the short term I just need to get this vessel operational so I can use it for work so I am going to be working with the outdrive unit I currently have. Once the cash gets flowing I can consider upgrades. Out of curiosity what is so punishing about these? Is it an issue with durability, or availability of parts?

Hystat, thanks for the idea to shift it into gear and check the rotation! I will be checking this tomorrow. If all goes well I will order the necessary gaskets etc. for re-attachment. I will keep this thread updated with the results so you can check back to see how it went.

Should I be worried about the rust on the drive shaft?

Thanks again Gents!

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theydrewa31 said:

.........
Out of curiosity what is so punishing about these? Is it an issue with durability, or availability of parts?
When working well, they appear to be fairly durable.
Parts are still available.
The down side is:
... it's a Dog Clutch drive.
... the company is no longer in biz, and has not been since the end of 1993.
... few people today know how to or want to work on them.
... the require an ESA (electronic shift assist) that is finicky.
... the lower shift cable adjustment is finicky.


Hystat, thanks for the idea to shift it into gear and check the rotation! I will be checking this tomorrow. If all goes well I will order the necessary gaskets etc. for re-attachment. I will keep this thread updated with the results so you can check back to see how it went.

Should I be worried about the rust on the drive shaft?
NO!

Although you said that the gear oil has been drained, I would pull the plug and let the drive sit over a container and view the remaining bit of oil.

Click to expand...

I've had one, and have owned it 18 years. When I first got it, there was still a very good OMC tech around, he got it up and shifting well about 2004 or so. I have since learned how to do it myself, and am pretty well versed in the Cobra quirks and have sources for parts too (this site is a good one for example, I get NLA stuff from ebay, etc). Now I was going to do the Volvo SX conversion but this one has been so good to me that I wound up not really seeing a need to spend what it would take, to get a good condition SX drive, the pivot housing has to be changed, then add the raw water pump. Parts total approx 4000. What I did, was fine a very good condition Cobra drive as a spare back up to my original, and I have a collection of spares for things that are not that easy to find. The spare drive cost me less than 1/4th what the total cost of the SX conversion would be. So, I'll keep running the Cobra(s) for now. When set up right they shift great I can tell you that. Easy to work on, and durable. Mine sits in salt water 6 months out of every season. Very few repairs on the drive and transom mount.

Take a look at the thread I just posted. I'm a 45 year automotive tech. I've done everything in the business. Never before have I had so many issues with a particular component or or automotive system. Next boat is going to be a Mercury system. http://www.marineengine.com/boat-fo...lease-help-or-I-m-going-to-blow-my-brains-out!

jhonster said:

Take a look at the thread I just posted. I'm a 45 year automotive tech. I've done everything in the business. Never before have I had so many issues with a particular component or or automotive system. Next boat is going to be a Mercury system. http://www.marineengine.com/boat-fo...lease-help-or-I-m-going-to-blow-my-brains-out!

Click to expand...

Then after those frustrations, you’ll hopefully switch to Volvo Penta.

Take a look at the thread I just posted. I'm a 45 year automotive tech. I've done everything in the business. Never before have I had so many issues with a particular component or or automotive system. Next boat is going to be a Mercury system. http://www.marineengine.com/boat-fo...lease-help-or-I-m-going-to-blow-my-brains-out!

In regards to what you should do. Make sure the input shaft seal isn't leaking. If it looks wet around the ujoint yoke, you might need to replace that upper seal. Otherwise it will leak gear oil into your upper bellows. As others stated, turn the input shaft clockwise while moving the shifter rod up and down to see if you've got forward and reverse. Lots of tech videos online regarding the repair & maintenance of these dog clutch cobras around. Look up Michael Romer on youtube or TC Electronics and Marine with Wayne Koll. Check the prop shaft seal for cracking or wetness as well. I would put the prop on the propshaft & tighten it. Spin it to make sure there's no run out, like the prop shaft might be bent. That would need to be dealt with before using it. Ck the ujoints for any excess play.

The area of rust on the input shaft isn't in a critical area. Its not a bearing riding surface. That area pushes into the gimbal bearing at the back of the boat, so it doesn't spin. The race of the gimbal bearing is what spins, not that area of the shaft, so no big deal. You can use some fine sandpaper to get rid of it. Make sure you grease the splines & those areas when installing the shaft with Mercury hi performance grease or equivalent. Install the unit, put some water ears on the stern drive to feed the motor water & start it up. Ck to see if your ESA system is working. ESA is an electronic module that works in conjunction with some switches on the shift cable bracket which makes the engine stumble & lowers the RPM to get in & out of gears. You'll hear the engine sound like it's blubbering going into forward......totally normal. It's important the engine idles around 500-550 RPM to get in & out of gear easily. You should adjust the idle mixture of the carb to get the cleanest most even idle as possible. Not too rich or too lean. Just right. Hopefully the water pump on the stern drive is working well to provide water to the engines water pump. You might even want to take the top plastic cover on the unit off (three 3/8ths bolts) and check the water pump. The pump comes off easily (three bolts) and you can check the rubber impeller. I usually put a little grease in those to make sure they'll be ok. Those impellers are usually good for a couple of seasons.

If I'm looking to see how well the inside of the unit looks, I'll remove the input shaft by just removing the 2nd ujoint clips and tapping the shaft and constant velocity joint off. That allows me to turn the input yoke easily. I'll also remove the water pump so I can feel the backlash on the gears. I'll take the top inspection cover off where you check the oil level so you can inspect the gears & the tooth contact pattern. You can get a feel for how the bearings feel with turning the input shaft in neutral. Try shifting into reverse and fwd and taking into attention that the shift shaft moves the same distance going into fwd vs rev. A good indication that there's nothing wrong with the dog clutch. Too bad there wasn't any gear oil in it so you could see the condition of the fluid and whether or not there was metal in the unit. At either rate, make sure you get the correct fluid pump & pump new gear oil into it from the bottom. Follow the procedures in the videos online. Basically you remove the lower plug, fill from the bottom. Open the center plug which is on the same side as the bottom fill plug.....pump fluid till in until it starts to come out. Put the plug back in the middle. keep pumping till you get 2 qts in. Check your level on the top. If the drive is working well, it will go in and out of gear easily without much grinding or clunking. And you absolutely MUST notice the engine burbling going into gear to verify the ESA is working. Get outside the boat and listen to the unit that no major noises are happening. Good luck

Hello again all. Sorry for not updating this thread for so long, life has thrown me nothing but curveballs. This past year has really knocked the wind out of me with car breakdowns, family health issues, death in the family and business screeching to a stop to top it all off. Anyhow I have finally been able to focus some time on my boat again. Jhonster thank you so much for the detailed information. I started work through the diagnostics you recommended.

It seems as though I am able to shift into forward and reverse as the propeller shaft spins freely when in neutral, then engages when shifted into gear and becomes difficult to turn, however spinning the drive shaft does not turn the propeller shaft. A look inside the top plate reveals that as the gear on the drive shaft is turned the motion is not being transferred to the gear underneath. Its beginning to look like this thing is going to need some work.

I was able to find a tech nearby that will work on it, but I am interested to see how much of this I will be able to do myself as I need to keep cost as low as possible. I did look into the SX option that some of the people on this forum had recommended, but quickly realized that option was far out of scope financially speaking.

Unrelated notes: I discovered this boat must have been stored in the snow without a cover. Lots of water damage to the deck wood. I had to completely tear it out along with the water logged deck foam. I discovered that the transom wood is disintegrating, so that will need need to be replaced as well. Nothing but hard work ahead of me.

Sterndrive engineering makes a conversion kit so you can install a Mercruiser Gen2 Alpha drive.

Thanks for the idea Chris. I would prefer to go that route, but after crunching the numbers it looks like my most affordable option is still going to be to just get this current OMC outdrive working properly again. If I had the extra coin, I would go for it. Unfortunately for now this ol'girl will have to wait a few more years before she gets a fresh outdrive. At that point hopefully I can afford the SX.

I am hoping to begin my tinkering in the next week or so to see about identifying the failing components.