Engine break in after rebuild

[erionmustafa]

Hi i just did a top end on my 1997 dt125r i heard that you should take it slowly after rebuilding it not give it much gas and all that what should i do to be safer

[Rallyfinnen]

If it's a standard cylinder with iron sleeve it is more important to run in, a nicasil cylinder is not so critical. With iron sleeve, first do at least one heat cycle only idling. You can add an extra 1% oil to the fuel the first tank or so.

[Calum]

I think the main thing are the piston rings bedding in.

I haven't worried about it too much. 50 miles if it's just a top end. But I am quite happy to rebuild the engine prematurely.