Honda HRN536VK speed adjustment, mower too fast

[anynick]

I have just bought one of these. Just tried it out, it started fine and all seems OK, but not cut the lawn in earnest yet. But it is clear that the maximum speed of the mower is way too high, I would need to run and I doubt my wife could keep up with it. It has the Smart Drive control, a grey paddle on the handlebar which you press to engage the clutch - the further you depress it, the faster it goes. Maybe we will get used to carefully regulating the paddle to keep the mower down to a speed we can walk at, but I'd prefer it if the maximum speed is about a fast walking pace, so it never runs away from us. Can I adjust the Smart Drive cable to reduce the maximum speed? I appreciate this means the clutch will never be fully engaged, but then it won't anyway, else we can't keep up with it. Alternatively, maybe adjust the maximum engine speed via the carb somehow?