A interesting read about engine break-in.

[Vince77]

Makes a lot of sense to me, but I'm sure there will be different opinions about it.

http://www.mototuneusa.com/break_in_secrets.htm

One instance that adds to this theory, a friend and I both bought new quads (mine was the arctic cat DVX 400, he got the Suzuki LTZ 400, same quad different body). I broke mine in fairly easy like "you're supposed to", my friend ran the piss out of his right out of the gate.
My friend has probably 75-80 Lbs on me easy, yet he was always faster that me and my quad. Straight ahead or on a track. Now, obviously there can be power differences even though they are same motor. But not that much.
Just sayin', seems like there might be some truth to it.

 

[X-roller]

Guess this explains why I beat my buddy's xrunner when I was stock and he had a cat-back exhaust every single time....

 

[RRCanuck]

Thats some interesting shit right there. Ive always heard breaking in a new engine is a thing of the past with todays cars and trucks. Ive never heard of this theory though but I like it. Haha. I cant imagine having to baby my new car for a bunch of miles before I could really hammer it.

 

[Murderface]

Did the same thing with my Xb since it had 3 miles on it and it seemed quicker then the one I test drove.

 

[burnboy]

Some engines are broken in pneumatically before placement. With compressed air

 

[Live...Ride...]

I always think it is a good idea to break everything in first, take it easy, definately hard to do tho

 

[Scarface]

Meh, my bike runs just fine after 10k miles.