Hello greetings from Singapore!

I am Francis.
I just bought a 3 years old XT660Z last week
with 19,800km mileage on it. I am the 3rd owner.

So first thing i did was to give her a new engine oil + oil filter.
Took it out over the weekend and had a blast!

• Suspension is too soft for both front and rear. Will fix that.

• Bikes got lots of backfiring when closing throttle. Bike comes with LeoVince slip-on exhaust. Is that backfiring normal..?

• Tyre is gone as well. I am looking for a 70% road 30% off-road usage. Any great tyre to recommend?

• Upon other inspection i found something underneath the seat which i could not identify what is it for? I also don't have the manual to refer to either. its a small little black box approximately 4cm X 4cm and 1 cm thick with a knob about the size of a toothpaste cover that can switch clockwise from 6 o'clock position to about 5 o clock position. it has a thick rubber wire housing attached to it that ran to somewhere underneath the petrol tank. I wish i can post a photo but i can't. Am i making any sense here?

Would hope to learn more from you guys.
Thanks in advance.