For what purpose are you buying a bike?
What's the budget like? I use a bike which is
now an antique...so they say. 34 year old Yamaha.
2 stroke. very good quality.solid iron all around.
Love it and use it often to go into PJ/KL during peak hours.
Pre-owned is good but get a bike mechanic to check it out.
Cant advise much cos unsure of your budget.

i am not sure where u stay but there are a lot
of bike shops selling pre-owned along the NPE near to Sri Manja.
Landmark is Shell and many bike shops.When free go and scout for
a good one. Ask questions and go for a test ride.