Oil Breather Issue

[fatboy]

I cant help thinking this is a scavenge pump problem as the cylinder compression test gave good results, a microscopic piece of crap can stop the whole puzzle from fitting.
prize bummer for you mate

[falcofreddie]

Right, just to satisfy anyone who's curious to know about what was wrong here - have been in contact with Carl and it was apparently a cracked cylinder head - previous owner/ garage had apparently adjusted valve gear, made a mess of it, wrongly fitted head bolt, over tightened it and the crack gradually developed over time...hence excess crankcase pressure. Needed various new bits including cylinder etc.
If anyone's interested, it's currently on Carl's site for sale at what looks a pretty decent price

thanks again for everyone's help.......

[D-Rider]

Ouch - that's a nasty one.

Thanks for the update.

[fatboy]

Not sure I can get my head round this as the compression test said good, then again my only understanding/qualification is of the oily rag type