Like it says above - just spent the day tinkering, replaced all the exhaust gaskets and is no longer blowing!
Checked the valves and they were all out of spec adjusted them, rebuilt checked after cranking for a good while and all was in spec and rode to work, noticed at the lights that i know...
The back brake on my bike currently makes a high-pitched screech (the way London taxis and buses often do.) I'm wondering if this is a simple fix or if I need to take it in? The bike's only a few months old.
Any clues would be gratefully received.