Hi Skippi, A 16T front sprocket is too big to use without grinding away some clearance, at least that is what my research says. I'm into reversible modifications plus I already have access to smaller rear sprockets ( 39T, 37 T and 33 T) .
The weight change would be too small to make a noticeable in fuel economy. I would'nt mind a single can exhaust system but I don't want something that is going increase horsepower at the cost of fuel economy. The battery that came with the bike is pretty small already. The stock pre-gen Ninja is already a pretty light bike ( 304 lbs. dry).
Another factor is cost. If I have to spend hundreds of dollars to save fuel I have to look at the return on ivestment to achieve it. I started this project as a demonstration of how a low cost motrcycle with low cost modifications could return world class fuel economy. So far I've onlty invested about $850, including the cost of the motorcycle.
Excellent questions, thanks for asking.
all the best GA