oil filter screen is located on the clutch side. it catches dirt/metal debries/shavings from engine oil.. from leting them circulate in engine..
they are best to be cleaned once.. but if not it wontr hurt much..
it doesnt need engine too be openewd bu the rght side clutch cover needs to be removed .. just like the left side ius removed lways.. but right side has gasketas well as that side keeps engine oil.. so if poper fitting is not done it will leak engine oil..
and where is the other oil filter locate ? is that for engine oil or petrol ?