After 16 years it's back!
This thing endured my father, my brother and myself without any real engine work or maintenance. It just kept going. Some of my earliest memories are of my father sitting me on the gas tank and putting around the woods. I still remember back when I was 12 or 13 and kicking it over for the first time and taking off in the woods for the rest of the day - my dad's rule was that if I was big enough to start it, I was big enough to ride it.
I've spent the last 2 years slowly dismantling every piece, painting the frame, rebuilding the engine, etc.
Thanks everyone. This place was a massive help. I've gone through many years of threads looking for answers and almost always found what I needed - usually answered by feetupfun.
It's time to get some proper tires on it, build an airbox and climb some stuff.