Looks like you get to choose from these (depending on the year) Look at this chart & lots of great info here: http://www.maxrules.com/OMCplugchart.html
The 1977 model, 70 hp Evinrude outboard requires an NGK BZ7HS-10, or a Champion QL77JC4 Plug gapped to .030 in.
I use the QL77JC4 Champion plugs with a 0.030in gap.
70hp. what premix ratio do you use?
Evinrude and Johnson outboards decipher the year model of the engine, by use of the engine model number.
If it is a 2 cycle where you mix the oil with the gasoline then use 2 cycle marine oil. If it is a 4 cycle then use the weight recommended by Evinrude.
i got a 75 hp evinrude with a 6.6 gallon fuel tank it use 16 onces of oil
1959 thru 1963 Johnson and Evinrude use a 24 to 1 ratio. 1964 and up is 50 to 1
The Evinrude 9.9 model with the number 106546 was produced in 1986. This model is part of Evinrude's line of outboard motors, which were popular during that time for small boats and recreational use. If you're looking for specific features or specifications, further details can be obtained from Evinrude's historical archives or motor manuals.
The 1990 model, 90 hp Evinrude outboard can use either an NGK BR7HS, or Champion L77JC4.
Four stroke
I have the same motor and use 50:1.
A 1979 70 HP Johnson burns about 3.5 GPH at 3/4ths WOT