The valve clearances for the SR125 are with engine Cold. Inlet 0.05~0.09mm ( 2~4 thou ) and Exhaust 0.11~0.15mm ( 4~6 thou ) with the engine at TDC on the compression stroke. It is also worth checking with the engine in the same position the cam chain adjustment by removing the cam chain adjuster cap behind the cylinder and making sure the threaded adjuster is flush with the end of the pushrod ( inside the adjuster ) .If not loosen the large locknut and turn the adjuster until it is flush with the end of the pushrod, tighten the locknut and replace the adjuster cap. Hope this helps. Tony.
