Hey guys. Just wondering how many miles I got to break this 400 in. I have 2.5 miles so far, but I haven't got any long hard rides yet. I don't have a license or anything. So I open it up hard to seat those rings. No babying, but in residential neighborhoods I can only do so much. Should I put er' away until I can do a proper break in, so as not to lose the honing before the rings seat. Thanks.

I break mine in per owner's manual. 1975 DT400 manual says avoid prolonged full throttle for at least first 500 miles. Goes on to say 0 to 100 miles avoid operation above 3000 rpms, 100 to 250 miles not over 4000 rpms, 250 to 500 miles avoid cruising over 5000 rpms, beyond 500 miles avoid prolonged full throttle and running over 6000 rpms. That's how Yamaha says to break in a new 400 motor. That 's how I broke in my 76 DT400 this summer. I have 800 miles on it now. Good luck.

Thank you bro.