I have seen so many members concerned about engine revving in the break-in period. So I want to share my experience and suggestion regarding this.
Also, I understand a lot has been already said on the topic, so please excuse me for starting a new topic. I started it so that it is visible to everyone instead of replying in some other thread whose title is not related to engine revving.
So, I have a friend of mine who works for PIA maintenance in Karachi. Aviation is also my favorite subject. So while discussing the largest and most powerful aircraft engine in the world with him, the mighty GE-90, which, by the way is being used in Boeing 777-200s in PIA's fleet, can offer 115,000 lbs of thrust equivalent to a staggering 145,000 HP! But for longer life and low maintenance costs, he said, a GE-90's output power is capped to a value lower than its capacity.
Now we all may appreciate that an aviation engine is one of the most sophisticated machines in the world. So when those engines are operated under capacity for a longer life, engines used in our local bikes should not be revved to their limits too. So I suggest that a 70cc be always driven at a maximum speed of 60 - 70 km/hr, a 100 cc bike at a maximum speed of 70 - 80 km/hr, and 125cc at maximum speed of 80 - 90 km/hr. Just make sure you do not push your engine to its limits.
For break-in periods you may ride your rides at roughly half the above stated speeds according to your machine. Rule of thumb: during break-in period, rev your bikes to speeds which your bike's manufacturer suggests for best ECONOMY. Also maintain that speed after first 1,000 km to obtain best mileage from your machine.
Hopefully it would give our engines a longer life and us a more joyful and economical riding experiences.