Ive been building/rebuilding my engine several times and if i change a bore kit, I always follow the hard breakin process by MotoMan.
Basically its the opposite of the process of manual booklet style break-in process where you “baby” your new bike.
ride it slowly, Dont rev up,etc…
Well i believe the reason why factories advice that kind of “baby” breakin process is to save themselves from returns due to factory
defects or due to misuse of owner during the breakin process. Manufacturers are super cautious. They prefer the slow route of breakin
over the faster route where it will give them higher liability and returns due to misuse/improper engine break-in process.
So Manufacturers prefers the safer/economical side for them 🙂
As long as its properly done, doing a hard breakin is Good for you and your engine.
it will make your motorcycle run faster, more power compared to other similar bikes that follows the manual booklet “baby” breakin process.
The main idea of engine breakin is to properly seat-in the piston ring to the cylinder wall. That can be achieved by putting “load” to the ring
to expand it well to scrape off the micro peaks in the cylinder wall. This will give your bore best sealing ever with best performance.
Now to provide load to the ring, You need to accelerate hard! That can be achieved by revving up your throttle the moment you get your bike
or built the engine. Just make sure that your engine is in normal operating temperature.
Thats idling it for 2-3 minutes then do the hard break in process.
-Rev up your throttle in every gear (but not the top/last gear)
-Decelerate by downshifting
-Vary your RPM/ Play with the throttle
-Wide open the throttle no more than 5 seconds
-Do it several times
-Change oil after the initial break in process is done (around 50-100kms)
See this video for clearer details