I usually break in fairly close to how the manual says to do it. If there's any deviation from that, it's only to idle the first tank, or to lift the vehicle off the ground and manually rev it up as the manual states(that car didn't have an Rx crystal, but the LHS traded me the Tx crystal for a set of Tx and Rx crystals). I take as much time as is needed to get the job done properly, and I don't like to stop in the middle of a tank unless the manual says to or it is absolutely necessary(i.e. friend stuck outside in 0 degree weather and needing assistance to get back in). I've had my 4 Tec for over a week now and I still have one more tank to run through it to finish the break in procedure, but that's not doing it all at once. I do think that it's all neccesary, but maybe not exactly how the manual says to as long as the first couple of tanks are taken easy and very rich.

I think that break in is very important. You even have to break in a brand new car before you can drive it how you normally would. Break in helps to get all the pieces to where they're supposed to be(i.e. expand the piston sleeve) because the factory can't adjust for the expansion and contration of the pieces while in opperation due to temperatures in the engine. In the long run, it will also help the engine last longer.

Break in is probably the single most important thing you can do for your RC's engine, but don't forget the after run oil either.

Good topic to let experienced nitro drivers share their oppinions on the subject to help newbies to nitro get started off right.

BTW revo, I'll be breaking in my new X-Term this weekend to, so don't feel bad. Not to mention that a buddy of mine might get him a nitro this weekend, so if he does I'll be helping him break it in as well as my X-Term.