mixing 2 cycle oil?

[Leroy22]

i have a 120hp mercury force inboard,just got and the oil holding tank is half full and i have no idea what brand of oil is in it. My question-- is it ok to mix different brands of 2 cycle oil? don't want to drain if i don't have to, scared of air lock.

thanks:Leroy

 

[racerone]

If this unit is " new to you " do this.---Mark the oil tank level.---Then mix gas and oil at 50:1 in the gas tank.-------Run the machine and monitor the oil level in the oil tank.---------The machine may smoke a bit more but you will not do any damage to precision parts.---Add a good brand of oil to the oil tank once you confirm it is indeed working.----No need to drain the oil that is in there now.

 

[ibnfshn]

Make sure the oil you use is rated TCW3