I will be putting in a new piston and new oversized jug on my zilla this week and was wondering what procerure do you guys follow when breaking in a new piston? The service manual says no more than 1/2 throttle for 10 hrs. Some other guys say only 1/2 hrs. Some guys say no synthetic oil during breakin, Some guys say it doesn't matter!! What do you guys think?

 

Go to duncan racings website and read their break procedure. www.duncanracing.com
These guys have been building 2-stroke and 4-stroke quads engines for a long time and have won every type of quad racing title, so I think they know what there talking about. I use the procedure to break in all my quads.

 

Some people say "Ride it like you stole it" for break in...

I'll agree with lt250r91, The last rebuild I went through an extensive break in period... Time will tell if it makes a difference.