How do you break a 81 250R top end rebuild?

[Adam250sx]

G'day guys, I just had my air cooled 250R bored out and new piston and rings added. What is the proceedure for breaking in the motor? I have search the site and can't find any info. What I heard is that you should not use the powerband for the 1st couple tanks of gas, is this true?
THanks
Adam

[TimSr]

If its just a top end break in, about a 1/2 hour of run time, keeping it under 1/2 throttle other than brief blips is adequate. Use your normal fuel mix.

[SPD FRK]

If your gonna race it just go race. Race pistons should be changed every thirty hours anyway. I doubt you are racing it though.
Dont hold it any certain RPM for too long. Vary the throttle alot and dont peg it at any point. If you want to go faster shift up. Do this for at least 2 tanks of fuel and you wont have a problem.
It takes longer than a half an hour to be certain.
Just so you know, I learned this from the manual and practiced it on the 82 version of your machine. Same engine.
Either of these replies may be slightly inaccurate so you will have to decide whether to use the more cautious of the two. TimSr may or may not have more experience than I do. I will just point out that once you do it the wrong way, its too late.