50:1 the extra oil will not hurt anything and gives extra protection while it sits between running timesMe again last year i had a dt 25 1984 2 stroke and it had a sticker with the oil gas mix was 100/1.Yesterday i bought dt 25 2 stroke 1985 with no 100/1 sticker on and the preaviest owner use 50/1 oil gas mix.And i read on another post someone said even if you have a sticker saying 100/1 oil gas mix this is no longer good the right mix should be 50/1.What is it ?thank you...