This could be a repost but here it goes. http://www.mototuneusa.com/break_in_secrets.htm I'm not sure what I believe. It kinda makes me want to open it up and rebuild right now. Either way, its a very interesting read. Opinions?

 

Interesting point.

 

interesting repost

 

This thread pops up every once in a while. It's a fun read, but personally I'll stick with what's recommended in the manual.

 

He sounds very educated and makes an interesting point but its hard to trust a web site with some guy, versus every car company that states how to break in your car. I understand that if his case is better, it would be hard for teh dealership to suggest to customers to fully warm their cars and run it hard, or dyno the shit out of it.

I'd go with what the manual said cause if something goes wrong, you followed the manual and your under warrantee.

 

Well, how does the dealership know if you followed the manual? They don't. I don't know what to think. I agree that he sounds very educated and brings up very good points and evidence. Just something to quell over I guess. This method could make the ring seal very strong but it doesn't say anything about a seized bearing. That is another main reason for breaking in slowly; no?

 

I had always heard that a car will perform to the way it was broken in - "Break it in the way you intend to drive it". You want a fast car, break it in hard. If you don't 'push' it during the recommended break-in period the car will not be as quick nor responsive (this is relatively speaking). That's not to say that I necessarily always follow that advice to run it hard from the start, but I have done so on occasions without any adverse effects.

 

I don't suppose the fact that car engines run 100,000+ vs a motorcycle engine running xxx hours before a rebuild has anything to do with it

 

I have broken my bike in both ways and I can't tell the difference. I broken in about 8 top ends and one bottom end in the last year. I like breaking it in hard better though, just because you don't really break it in, you just run it. I haven't tried that technique on a 4 stroke though.