Fuel oil mix

I have a 1973 4 HP Mercury 2 cycle. I'm trying to determine the proper fuel/oil mix for it. I found a manual but it talks about using an oil injection system AND mixing the fuel at 50:1 to achieve a 25:1 ratio. Things I've read over the years is that the oil injection systems were notoriously unreliable. Does anyone think that just mixing at 25:1 in the tank is a bad idea? I bought a manual on-line but it seems to cover all Mercury engines from 2HP to 80HP. Not sure if I'm missing something that might be different about these smaller outboards.
I'd appreciate any input you motor guys can give me.
Thanks
Steve

Mix 50:1 & you'll be OK.

crazymanme2 said:

Mix 50:1 & you'll be OK.

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