Yep, Euro bikes are mostly crap not withstanding our geographic reliability and longevity requirements.
Now regardless of your current season length I think bikes speak to our open steppe spirit. Our ancestors domesticated horse after all

PDF manual should be available over the net, I have seen few good leads with just simple search. Hardcopies are also popping up from time to time on the feabay.
Another idea is to look for other applications, I am not familiar with 400 engine but I am sure they stuffed it in other, hopefully more populous motorcycles.