I done a quick search and came up with a MK 55lbs 12V tiller handle 5 speed. MK 70lbs 24V tiller handle 5 speed.I could not find MK in variable speed but I did see MG in a 70lb tiller handle variable speed. All I done was a quick search. If you look more in depth you may find exactly what you want.

Here is a couple of links to look around in.

http://mk.factoryoutletstore.com/cat...ta-SPLT-B.html

http://motorguide.factoryoutletstore...FeRj7AodP2kAUA