boudreaux - Welcome and congratulations on the excellent bike score!
I don't know where you can download a manual in english but if you can't find one be sure to post and I'm guessing one of us could make a pdf, which is probably a good idea anyhow. As far as the starter goes, they use a Nippon Denso 128000-8840. There are a lot of them on ebay for around $80. You won't find them listed under that part number though, just search rotax starter (I think they're also used on John Deere light tractors). What makes you think the starter is bad? The starters are pretty good and if the starting system isn't working chances are pretty good it's the clutch sprag, not the starter. This site has _fantastic_ instructions on fixing that (see
http://www.mzriders.com/viewtopic.php?f=5&t=3939 and
viewtopic.php?f=26&t=4014) and very knowledgable and helpful folks to help you figure out what the real issue is.