I have just over 4 hours on mine now (crap weather and busy at work) but anyway, I go balls-to-the-wall on it everytime I take it out. Half the people I talk to say follow the break-in, the other half says ride it the way you want it to run. Everything I've ever bought new I have followed the break-in procedure outlined in the owners manual, so far I've been happy with doing so. However, a couple of my buddies bought brand new quads last year when I bought my 400EX used.
My one buddy bought a brand new 2002 400EX, he broke it in slow like Honda said he should and then put on a K&N, a White Bros slip-on and jetted it. The same thing my used 400EX came with. I don't know how mine was broke in since I didn't do it, but it absolutely smokes the 02 with the same stuff on it. It's faster everywhere, low, mid, and top.
Another couple of my buddies bought new Raptors within a couple weeks of each other. The one guy took it easy on it during the break-in and my other friend beat the w00ter out of it from day one. Guess what? Both are still bone stock and the one that has been beat on is significantly faster everywhere. Both quads run great and have both been ridden about the same # of hours.
I'm not saying that the quads that were beat-on will last as long as the babied ones, but they are faster. So I guess it depends on what you want to do with them, if you're into racin, beat on em, if you like crusin and want to keep it for a long time without doing any engine work, then take it slow.
After seeing these results I wasn't about to baby my new Z, and if it blows up, it's a good excuse to get the Big pappa kit and I will know better next time. But so far it hauls ass! I've really only ridden it twice, and the second time I rode it, she was definitely faster. I'm sure it will absolutely scream when I get 10 hours on it!
I will be sure to post something if this break-in process doesn't end up working for me in the longer run. I will also post some results if I get a chance to race another Z that was broke in differently. Have a good one!
99TL1000R