After a major engine rebuild you will want to break-in the engine so new parts can seat properly.
For the first 500 miles operate the vehicle at below 1/2 throttle then for 500 to 1000 miles keep it less 3/4 throttle. After 1000 miles you can use full throttle.
Be sure to lube all internal parts upon assembly as described in your vehicle specific manual. We like to fill the engine with oil and then turn the engine over by hand a few rotations before the first start. Do this just as you would if you were finding the top dead center and when the engine runs the first time we only run it for about thirty seconds then shut it of and recheck the oil level.
Keep in mind that small displacement, single cylinder vehicles, like a Suzuki DR200 for example, are not designed to run at full throttle for extended periods of time. When operating a bike like this treat the engine accordingly – it’s a good idea to roll the throttle on and off and never keep it at any rpm for an extended period of time.