jfwyatt1
03-02-2012, 07:41 PM
just finished putting the top end back together on my sons 400 and ran it long enough to make sure it has enough oil for break-in. Ive always in the past just run the heck out of my rebuils for about 30 min then changed the oil but the mechanic at my local shop who honed the cylinder said 400ex motors like a slow breakin period varying the throttle for about 10 hours. is this true or should i just do it as i always have. thanks