Repair of loose/slipping throttle on a TC 33D is actually a simple fix.
Remove two screws that fasten the instrument cluster and lift it out and move it to the left careful not to disturb the harness.
Look down with a flashlight, there is a 17mm nut that squeezes the throttle lever tight. But it has loosened over time.
It’s important to use a 17mm ratchet type wrench to access the nut and tighten it. You can tighten it as needed, check the lever to make sure it’s tight enough for your liking. I adjusted mine a little tighter.
Good luck
Remove two screws that fasten the instrument cluster and lift it out and move it to the left careful not to disturb the harness.
Look down with a flashlight, there is a 17mm nut that squeezes the throttle lever tight. But it has loosened over time.
It’s important to use a 17mm ratchet type wrench to access the nut and tighten it. You can tighten it as needed, check the lever to make sure it’s tight enough for your liking. I adjusted mine a little tighter.
Good luck
