Hello I need for a OMC Stringer electrically with a gear ratio 21:16

[red-flame]

Good day,
I have a stringer OMC sterndrive ca.1971 120-155HP with upper gear ratio 20:19 teeth ( CUFR19EX ) .
Now that I want to install an OMC Cobra 5.7L V8 from 1987 in the boat but will keep the drive , now I need a translation 21:16 .
Can you help me there?
I was told that I need to replace only the gears .
greetings from Germany
J?rg

 

[Scott Danforth]

welcome aboard.

if you want to install a cobra drive on a boat with a stringer, you need more than geers. you need to rebuild the entire transom of the boat, including the stringers and motor mounts.

if you want to install the V8 into the early stringer, you will also probably need more than a gear set. since setting up the gearset requires a bunch of shims and tools, you would be better off finding a replacement upper gear case complete.

are you removing a 4-cylinder and going to the V8? or going from a V6 to a V8?

 

[Bondo]

Now that I want to install an OMC Cobra 5.7L V8 from 1987

Ayuh,.... Welcome Aboard,.... That's a tough challenge, that probably ain't doable,....

The crank shaft bolt pattern changed in '86, 'n there's No way to adapt the newer bolt pattern to the ole stringer drive couplers,....

 

[southkogs]

On an electric shift Stringer, your lower gear case gearing should be the same as on a V8. The upper gear case will be a different ratio. If you're good with transmissions, you could probably re-gear but I would actually look for an upper that's already the ratio you need. Tough to find, but not impossible.

Beyond that, you've got the issue Bondo mentioned above.

 

[red-flame]

Thank you for the welcome greetings . My OMC Engine ( 4 cylinder 2,5l 120PS CUFR19EX 1971) this year was broken in order to not go on the boat transom must remained unfortunately I keep no other choice than driving . There was also smal V8 engines to block this drive and because luckily hardly anything has been changed to the V8 engines , it fits quite well ( of course you have something to order and to build ) Man grows with his duties . The only problem is just to come here ran in Germany OMC parts.

Either these are very expensive or there is none. Unfortunately, the shipping + inches from the States to Germany is very high. That's why I'm looking for most frequently used parts as they are a little cheaper . greetings from Germany J?rg

 

[Scott Danforth]

the OMC parts here are expensive as well. OMC has been out of business for a long time.

going from a 4-cylinder to a V8 you have a bit more than simple gearing to contend with. you still have to rebuild the motor mounts for the bigger motor.

your best option if you like the boat is to redo the stringers and transom for either a newer mercruiser or volvo-penta setup.

However ANY 2.5 liter or 3.0 liter motor older than 1990 would bolt right into the same location your current 1971 2.5 liter is. Mercruiser, Volvo-Penta, or OMC. you just have to use your OMC intake/exhaust manifold, mounts, bell housing and posibly the oil pan. the basic motors are all identical.

 

[Bondo]

The only problem is just to come here ran in Germany OMC parts.

Either these are very expensive or there is none.

Ayuh,.... It's the same problem on this side of the big pond,....

OMC has been outa business for well over a decade, 'n the stringer drives were poorly supported antiques even before OMC went outa business,.....