More than the usual tappet noise.

[Roy Gavin]

You could always try checking them the way 99% of the auto service guys check them - by feel with the motor hot and running at a slow tickover.

That way any excessive end float or wear in the rocker bearing becomes obvious, and it might be easier to source the sound too.

[sterob]

Have you started it with the rocker covers off Steve? Make sure oil oozes from around the rocker arms. A bit messy but a good test for proper oil flow.

[SteveD]

Yep, did that (Roy and sterob) at the last valve check.

The consensus at the Far Cairn boxerworks get together was that it's an exhaust leak as I'd thought. The leak can be felt around the star nut. buzz didn't even burn his hand!

I'll have a crack at filing down the compression ring to ensure it tightens down correctly. Last week I just gooped up the gap as a test, before tightening the star nut.

[2valve]

hi steve , i have some spare compression rings in my archives if you need any ( i think there all the same )

[SteveD]

hi steve , i have some spare compression rings in my archives if you need any ( i think there all the same )

Thanks Gary. I have a few too. Thanks for the offer.

[chasbmw]

You could always try checking them the way 99% of the auto service guys check them - by feel with the motor hot and running at a slow tickover.

That way any excessive end float or wear in the rocker bearing becomes obvious, and it might be easier to source the sound too.

If you did that there would be a hell of a lot of oil going everywhere!