I have a 1988 VLX 600 which is the first gen and it has two carbs and a fuel pump. Supposedly, it is faster but I don't know. It runs perfectly but when I go over 65 mph, I feel like I'm riding paint can shaker. The engine can handle it with no problem but I can't. This is OK with me because I've always avoided the interstate except as a last resort.
Some VLX owners have gone to a smaller rear sprocket for better gas mileage but that reduces low end power. I understand the European version (Steed instead of Shadow) has a 5-speed -- this would be the best solution.
For a small bike with excellent power and speed with great gas mileage, try to find a Kawasaki Vulcan 500 which has vertical/parallel twin cylinders, 10 more horsepower and 6 speeds. I had one and regret selling it. It sat just as low as the VLX 600 and ran perfectly. The engine and drivetrain are supposedly the same as the Ninja 500.
