in my opinion you should give more time before you opt to make any changes like suggested removal of duct. because without removal of duct ybr g 2020 i have, hit the 120 kmph with rpm in range of 8.5-9k. its just 1.2k mileage. here are my suggestions:
1. keep your filter and spark plug clean and lubricate your chain every 5~800 km onwards; i use 80w90 gear oil for chain lubrication; if anyone is interested to know why gear oil, well it sticks to chain better than engine oils or other stuff
2. use yamalube 10w40 if you want to try thinner oil without compromising your engine warranty
3. as you have already completed break in period, go for full but gradual throttle on clean straight roads at least twice a week; not everyday
4. keep your warmed up idle rev around 1.3k and don't rev your engine without warming up; i always wait 2-3 mins after switching it on
5. the most important suggestion i've for others and trying to comply with: keep calm and enjoy the ride and try things one by one instead of worrying about lots of things at same time.
