Good advice from the others there but I would like to add what I like to do after the initial start up, as you probally know you should be filling the engine with mineral oil, any cheap stuff you can find will do. I'm in the middle of doing a YB rebuild myself which to be honest is my first but below is the procedure I've used with other engines to good effect. If anyone knows a better way with the YB then please let us know.

1. After 20 miles of below 3500rpm driving change the oil and filter - again use mineral oil.

2. After 20 miles of below 3500rpm driving change the oil and filter - again use mineral oil.

3. After 100 miles of varied driving change the oil and filter - this time use a recomended brand/grade - opinion varies as which is the best.

4. Clock up at least a thousand miles without driving the engine too hard to bed everything in nicely then change oil/filter again then continue with your normal oil/filter changes.