Motorcycle Repair: 2005 V twin VENTO (250cc), engine case, v twin

Question
I have a leak between the tranny case and the engine case.  The bike is 1 year old and never leaked until I rode it for two days straight with not much rest between rides.  Also it over revs when I reach top speed (70 mph for this little bike) why?  You can find all the specs on this bike if you go to www.vento.com (the V-Thunder Cruiser is my model)  Thanks,
Regards
Charles

Answer
Hi Charles,

Sorry, I have no experience with this brand.

The website would not open beyond the home page with intro display.

I cannot explain the over-revving without investigating the problem. It may be a variety of causes. Each needs to checked via troubleshooting process of elimination.

Respectfully,
Mark Shively