Yeah, I don't suspect that one would handle so well. Although it's in the excellent 1981 frame (despite a few other styling cues which make it look much older) the Maicos were really dependent on their engines for handling. I've read that people tried putting Japanese engines in their Maico frames, thinking they'd create something amazing, and found that their handling was all shot. Maico engines were just so different from the others (I believe they spun backwards, until 1983 if I'm remembering correctly) that the rest of the bike was built around the engine doing the things it did. It'd be like if you put a small-block in the back of a 911, I suspect it would be radically different to drive (beyond the obvious weight and power issues) simply because of the dynamics of the engine-chassis interaction.
That said, I pity the fool that challenges this thing in the quarter-mile, especially if it's tuned properly.