Do not put oil in the tank ! I leans out your jetting . Read the notes on jetting if you are not sure .
Honest advice is to get a load of jets , find out what your local atmosphere pressure is compared to PI , compensate for the change and go up 1 or 2 sizes . The easiest way is to jet it rich , it will splutter at 11000 for eg , jet down 1 size and the splutter will raise to 12000 for eg , jet down 1 more size then it should rev to 12500 easy and still be safe .

A 16T sprocket , if you can't find one , you get the ns400 front sprocket , surface grind it down to the same thickness as the normal sprocket and then get a spacer to line up the bolts and the chain . You need to put the angle back on the teeth , quite a job !

Gear it so that it just peaks before the brake marker at the end of the straight