Repeat valve stem damage on a newly rebuilt engine.

I'll get into trouble here for saying it and I have no intention of entering into a discussion but I can't avoid the suspicion that 'modern' fuels might contain less lubricating compounds and be less forgiving than the greasy low-octane stuff that was used for years.

If you're shopping around for valves and want the best available for our sort of motorcycle then I don't think that you'll do better than G&S Valves of Godalming.

http://www.gsvalves.co.uk/assets/vintage-motor-cycle-catalogue.pdf

email (option): bsansw1@tpg.com.au

Hi

Thanks for the input everyone. I'll recheck the ignition while the head is off, but looks like my main work will be some light reaming and relief of the valve stem where the seize marks are. I'll pop the needle up one notch while I'm about it just as a precaution...and keep some additional upper cylinder lubricant in play for another few 100 miles, maybe just the 2-stroke oil as that's easier to hand

I'll update down the line

Cheers

Richard

email (option): dickie.bobbie@hotmail.co.uk

Check to see if you have oil going into the tappet cover as some pattern gaskets dont have the feed/drain hole cut into them.If you remove tappet cover then kick over engine you should be able to hear engine breath or fire up engine and see whether their is oil being blow around tappet area.Guess most of this oil mist is for tappet lubrication but some gets to valve stems... Dave

Appears to be all sorted now, at least on the basis of a reasonably long run and some higher speed (hahahaha) parts.

Yes Dave, plenty of oil and I double checked the oil hole in the gasket, I always seem to worry about blocking oil ways.

My trouble aren't over though, but that's another thread relating to the chaincase.

email (option): dickie.bobbie@hotmail.co.uk