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Maintenance on a 1966 55hp Johnson

J

jslee

New member
" I'd like to know what si

" I'd like to know what size spark plug and gap,proper oil and fuel mixture and how to oil the lower unit of 55hp Johnson.Any other routine maintenance would be helpfull. "
 
"OMC (Johnson) did not

"OMC (Johnson) did not manufacturer a 55hp engine in 1966. What is the model number of the engine?

Joe
"
 
" Yes, that model number indic

" Yes, that model number indicates the engine is a 1969 model.

The original spark plug designated for the engine is a Champion L19V (surface gap) and later was superceeded to a Champion L77V (surface gap). However, I'd suggest that you try the Champion L77JC4 plugs, setting the gap to .030 as this may give you a better idle and result in less fouling at low rpms.

Use a fuel/oil mixture of 50/1 (1pt of 50/1 oil to 6 gal gas). A gasoline octane rating of 87 or more will be fine. The 50/1 oil must be marked as TCW-III (two cycle water cooled, 3rd generation).

The lower unit (Hydro Electric Shift) requires OMC "Type C" lube, also known as "Premium Blend". You cannot use the type lube that is used in the mechanical shift units.

Fill the lower unit from the bottom drain hole until it flows out the top oil level screw hole.

Joe (30+ Years With OMC) "
 
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