CB750A? Hondamatic then? Based on my search, I do believe that your ignition unit is the same as my K7 (K8 is also the same). Basically, the ignition doubles as your steering lock, correct? (Like the picture here)
First, do you have a manual? (Paper or digital) They are often available for free online.
Although I don't know Hondamatics specifically, since the ignition unit is the same as mine, that means it will be bolted onto the gauge cluster clamp (the thing that holds our gauges) from BEHIND (8mm bolts?). This requires that we remove the headlight (3 screws) and then detach -- but not completely remove -- the headlight bucket. If you're careful, you can just sort of wiggle the headlight down the wires just enough to let you get back there. The ignition is connected to a large, white plastic plug.
(If you move the headlight bucket, do be sure to check all your wire connections before putting the headlight back on) It is a relatively painless process, probably even fun for someone who enjoys wrenching.
If you need a new ignition, used ones are available on Ebay, however, used ignitions from this period are old, and that steering lock bolt can be stuck up inside. Normally, I'm all about buying used parts, but not with this particular part. If that is, you need one.
