1988 OMC Cobra stern drive

1988 Seaswirl Cuddy cabin 4.3litre OMC Cobra drive

Hello, I love the above boat but not the drive unit. I had the outdrive rebuilt, (2 years ago) the shift cables and the shifter control replaced. It hasn't shifted properly since and I have given up on the repair shop. I am a heavy duty mechanic and feel confident doing a conversion, I just want to get opinions on the best conversion out there.

What is the best most trouble free outdrive available for these boats? I know the boat is old; however, it's long paid for and it suits my family's needs.

Any help would be appreciated.

Thanks in advance for any help.

Cedric

http://www.sterndrive.cc/blog/sei-cobra-conversion-kit-faqs/


I'm not sure I'd toss the drive because it isn't shifting right. The factory manual setup starting with shift rod height in the lower unit can get these drives shifting like butter. However, many old boats don't even have the right lower unit on them which can make setup very difficult. But there's the conversion. About $2500 for the Mercruiser Alpha Style drive and conversion parts. I haven't tried it, and hear there are some challenges with it too, but that gets you a new drive with a 3 year warr.

The Volvo SX conversion gets you to a much nicer drive, that will always shift beautifully (cone clutch shifting), but the parts seem scarce and discontinued, and I can't figure a way to do it for less than about $6000

If those yard monkeys can't adjust a Cobra drive they should be in another business. It is REALLY easy. The most you need for special tools is a plastic protractor and triangle from the school supplies area at the CVS. Follow the directions in the manual or at Stuart Hasting's site and you will have it shifting like new. Promise.
If you do give up the ghost then you can swap any drive on the boat. Mercruser, Volvo, etc all use the exact same hole cutout and bolt pattern. The idea of buying a mercruiser leg to go on a Cobra drive transom is just stupid to me, when complete Alpha drives are available for a couple hundred bucks used. Yes the coupler is the same too. I've even started to see Bravo3 drives ion Ebay for about 2 grand.

Thanks for the response folks.

I was tinkering around with the boat today with the water wings on the drive - it shifts flawlessly FORWARD REVERSE NEUTRAL all combinations no problem. I am confused why it seems to be a problem only on the water; also, it seems worse after a long run. My only guess is that the lower housing is binding up when different shifts are required.

Any more thoughts as to what is going on?


Thanks again

Cedric

ever change the lower shift cable? they last 10 years or so.
some introductory reading:
http://www.hastings.org/~stuart/cobra/

As was noted in earlier post, read Hasting's article as it's really good and to me the definitive guide on setting up these drives. What are you idling at? You should be idling at 700-900 RPM and if you don't this causes harsh shifting. A lot of guys will turn up idle speed at the carb to compensate for bad engine tuning, and that in turn leads to harsh shifting and lunches your outdrive. There is also a shift interrupt circuit that momentarily kills the ignition when shifting gears. If that isn't working right, same result. If you are on the water, it can take a minute for it to idle down after a speed run. If this is so, replace the return spring on your carb. I too picked up an 88 Cobra 6 years ago and spent the effort to get everything adjusted right. It shifts like a dream.

Edit: Also, on idle speed the OMC factory manual is the only place to detail exactly how to do this and it involves measuring distances between points on the carb linkage. Seloc manual not helpful on this.