RE: Need info on old OS 120 four stroke
the pushrods and lifters are the same as the later surpass 1.20 engs. my eng. turns a 15X8 Master airscrew K series prop at 8500 rpm on the ground. i use 10% nitro and all caster Power
Master fuel. your short push rod has lost its temper and is wearing on the ends. pn #45566000 is the # for the pushrods. the same pushrods fit the FS 120S, SII,
sIII, SE, FT 120II and the FF 240 & 320 engs. i bought my spairs from Tower.