Repowering an STZ is a challenge.
The Kohler MV20 engine is an opposed twin with a relatively low profile and mounted somewhat under the operators seat.
Kohler Magnum twin engines have been out of production for a long time. All newer production is in a V twin design and with a taller profile.
The other problems are relocating the other machine components, some of which are hung onto the engine, muffler location and availability along with unforeseen hangups.
You may be able to find a machine shop that could and would overhaul your Kohler Magnum, parts availability may be a problem, a good overhaul could cost $1,500 give or take.
As for resale value of a repowered STZ, being a 1991 machine, value just isn't there and a possible new repower engine could cost up to $2,000 or more just for the engine.
