1. Go and view the bike – if buying on Ebay or online , can you trust a seller’s description? Have they used an original photo?
2. Listen to the engine. Pistons & re-plate can cost £300 plus. If in doubt take a knowledable mate along. Or visit local trials & get a feel (ear!!) for noisy engines!
3. Check year – some owners update the plastics.
4. Check chassis bearings – wheel bearings are cheap, other bearings are not, so check the suspension linkage for play. Chain & sprockets cost £55-70 so check .
5. Check tyres – “plenty of tread there mate” is not good enough you need sharp edges to the blocks.
6. Ask to see air filter and inside the airbox. Remove filter & look inside the air box. Nice & clean is a good sign, so maybe the owner has done some maintenance……
7. Ask owner to remove flywheel cover , rust & water here is bad – can affect electrics. Also spin the flywheel to check main bearing feel & vertical play, it should be smooth running and have no vertical movement.
I hope you find a good’un & enjoy your riding in this great sport.