Running On About Running In
I bought an '04 Kawasaki ZX-12, and it came with a sticker on the tachometer telling me to not exceed 4000 rpm for the first 500 miles. What do you think about this? I've been a good boy for 150 miles, and I want to let 'er rip. Is there something different about this engine? I've noticed not all brands have this sticker.
Via the Internet
There really isn't anything different about the ZX-12's engine in that respect, Forland. Actually, all new engines need some sort of running-in or break-in process before you flog the horns off them. And while not all brands have that precise sticker, quite a few do have one that warns the owner not to rev the engine past a certain rpm for the first few hundred miles. More on break-in from Kawasaki:
"As a new bike is being ridden, both the drivetrain and the chassis go through a break-in process. It is extremely important that the engine receive proper break-in. Engine component tolerances are very tight when new, so friction between moving parts is higher than normal, which creates higher than normal running temperatures. Extremely high temperatures need to be avoided, or serious engine damage might occur.
"Bearing surfaces, for example, need to form a match. If the bearing is overloaded during this break-in process, galling might result, which can shorten bearing life or, in the worst case, cause a seizure. Valves must seat in the head and rings must wear in to form a good seal against the cylinder wall. Otherwise leak-down will be excessive and the engine will never be able to reach its maximum performance. For best results, rpm should constantly be changing, with no long runs at a fixed throttle opening. It is also very important to make the first oil and filter change at 600 miles to remove contaminants that could later cause excessive wear."