Xflow rpm.

If she's an old one without a rebuild you will probably start to break rings first, hard to say at what revs but I wouldn't be any braver than 5000. She'll rev past that but the engine may start to breathe a bit.

Clean the lip off the top of the block and balance the bottom end and mine holds together at 7000 hapily. I've got a custom steel flywheel though, cracks started to pop on the original [:u]

There will probably be a load of posts disputing that figure, but I've got a clean non steel crank. My old 1300 held together happily to 9000 on a regular basis without too many dramas. Oil starvation was the bigest problems and the 1300 was getting a new set of bearings per event. Again, not a steel crank.