I don't know those vehicles at all but every shift cable I've ever seen has been a real tough thing that should last twenty years. You couldn't break one with muscles alone. I'd be looking for a problem somewhere before the new one broke.. Perhaps the cable's routed wrong so it has a sharp bend, or perhaps the engine mounts are loose or worn allowing the cable to be flexed constantly. Is it the cable that breaks, or the metal fitting on the end of the flexible cable. The shifting problem might be caused by one of those problems I mentioned, or it might be because the engine's idling too fast, or because the belt drive system needs a bit of work/setting up. The fast idling or badly adjusted belt drive though will not break the cable, they'll just make it hard to get into or out of gear. The breaking cables problem needs fixing first probably and then see if the shifting gets better. When it goes into gear, does the vehicle lurch forwards or graunch he gears ? Either of those are a sign the revs are too high or the belt's playing up. If neither of those things happen, then perhaps the hard shift is because the cable's misaligned.

Well g'day Kdog. I'm a now retired rural mech and I've worked on about everything too.. Not jetskis though.. not yet. One son bought a broken one a few weeks ago though so there's still time.