How many km to break in a new piston?

5v3d3b0 · World Chat Champion Joined: 24 Sep 2006 Karma :

How many kilometres should I do at low revs to break in a new piston? The cylinder has about 4500km.

5v3d3b0 · World Chat Champion Joined: 24 Sep 2006 Karma :

And how many km/h and revs should I do maximum during this period of time? I have the Yamaha TZR 50cc 2005

Chiz · Trackday Trickster Joined: 06 Nov 2005 Karma :

Most 2 strokes are around 500 miles i believe.

Try not to rev above 3/4 of the rev range (i know this will be difficult on a TZR 50 (i used to have one, needed redlining in every gear just to plod along!)

Make sure to vary the throttle, don't keep it at the same revs for long periods. Start off not going more than say 5000rpm, then increase the revs by another 500rpm every 50 miles or so.

That's what i'd recommend, other people may think different.

EDIT: why's it had a new piston already? mine lasted nearly 9000 miles without even an inspecton on the piston (that's about 14000 kms)

5v3d3b0 · World Chat Champion Joined: 24 Sep 2006 Karma :

This bike is gonna feel like a pile of crap now that Im changing it back from tuned, AND have to go slow...