oil mix ratio on older mercury

[Fish4Fun]

anyone know what the mix ratio is on an older Mercury 20hp electric start
serial # 5730301

[DaleM]

My 73 Merc. 10 hp. is 50-1. They have been that way for a long time. PM Lakeraider, he's our resident Merc. expert.

[LakeRaider]

The 7 digit serial numbers started in 1956, which would have been the Mark series. Being your motor is a 50-series serial# I'd say it is a very late 1978 or early 1979. That would make the mix 50:1 :cool: Raider<><>

[LakeRaider]

I might have missed on the year. It looks like a 1980-1985. After 1986 I beleave the motors started with the A9 seriaL #"S The mix is 50:1
Raider<><>

[Fish4Fun]

Thanks raider thats what i figured and i did believe it was a mid 80's just wanted to check with the resident expert on the merc's, she runs real good..

[DaleM]

Hey Raider. that what I thought also. I have that 73 also have an 85 in canada that uses 50-1. Darn I'm getting better with age.