Re: how to hook up hydraulic steering on a 1969 johnson 115.
I doubt that you have a hydraulic system, simply because very few people would have one on a boat intended for relaively small engines. Further, the charge system on your '69 115 only puts out 9 amps. Trying to run a hydraulic pump and a bunch of gear on the boat with a 9 amp alternator (stator/flywheel), doesn't stike me as a good plan.
Look under the dash at the back side of your steering wheel - you will probably see either a drum or a rack/pinion type mechanism, with a teleflex style cable hooked to it.
If you have a push/pull type system, you will need an adapter, since your motor doesn't have a tilt tube. You can buy a transom clamp assembly, but I recommend a system like the one in the photo below. The advantage is that it doesn't restrict the tilting range of the motor, which most transom clamp setups do.
Make sure that you get one that is rated for your size motor - there are many made for smaller motors (usually up to 40hp), so its easy to get the wrong one. Mine (pictured) is rated for up to 140hp.
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