o.k this is what we r to look for as per the rd guru ron-Engine:
Insist on seeing what oversize the barrels are. THis will tell you how much life the bike has left dont touch the bike if its on the last over size. New barrels cost 12-16K. And nobody can do a decent sleve in India yet. STD bor orignal are priceless. First over size are rare. Sleeved garbage is the norm. A sleeved bike will never run as good as the orignal because we dont have the metal or tools or skills to do a decent sleve in India. Expect a sleeved engine to put out about 18-24 BHP nothing more.
Take the bike for a ride. It should lift the front wheel with just the throtel no clutch.There is no mistaking a good RD when you ride her. Put it in first and whack the throtel open. Your body gets flung back. Your neck snaps back and the front wheel becomes very light as it leaves the Ground.
If it has been repainted well ok, Bad paint job then expect to sped a packet on geting it painted.
If its repainted most probally its been in a accident. Chk the foot peg levers and underside of the chambers and frame for damage. Chk the front fork legs they should be straight and no scoring marks.
If the bike has been in an accident it wont handel as well if the frame has been bent. Try and take the bike for a high speed spin i.e. over 150 see how she handles.
When accelrating. Accelrate hard thru the gears she should move smoothly without stutering check the red line. She should be able to rev to 6K for LT and 8.5K for HT in all gears under load.
Ask what jets he is running avoid a bike that has been running on anything smaller than 140.
basically guys if u ride a rd hard u should shudder when it enters the powerband at around 6 k for ht and 5k for lt.and it will then kick ur ass and will shoot from under ur legs.ur back neck hairs should stand.thats the rd 350 for you LOL