I need to top up the oil on my R125, but I cannot find anything in my manual or on google that actually says what oil I should pick up?! can anybody just give me a nudge towards any particular brand - specific oil?

Surely the manual gives you the oil spec? "10w/40 mineral/synthetic/semi-synth to API Specification SL" or summat like that? As for specific brands, all the quality ones are much of a muchness and should readily mix - so what's in the engine now? I've used Halford's own brand semi-skimmed bike oil for ages with no problems.

Rough guide:

1. Don't mix types if you can avoid it - mineral/synth/semi-synth. They should work together OK, but why risk it?

b. The API spec is the one you need to check - if your manual says SJ or better, don't put SG in it - but vice-versa is OK. The order is on the second letter, so SA is the oldest, SM (?) is most recent - S is for petrol engines (Spark ignition, maybe?).

iii. Don't be tempted by cheap car oils - most bikes don't react to well to them (long diatribe on friction modifiers and wet clutches ... avoided).

You're welcome

It is in spanish , but is the service manual for your bike. Where it says " ACEITE DEL MOTOR" ( ENGINE OIL) you can read :

TYPE OF OIL : SAE 10W - 30 , SAE 10W - 40 , SAE 15W - 40 , SAE 20W - 40 , or SAE 20W - 50 .

RECOMMENDED DEGREE OF ENGINE´S OIL : API service type SG , or superior , NORM : JASO , MA

¿ Or is it the brand , you want to know ?

YAMALUBE FULLY SYNTHETIC 4 STROKE MOTOR OIL PART NUMBER : YMD-65011-01-02