Fuel mix

[Aquafix]

I recently picked up a Sears 5hp outboard motor model#643-05 . Can anyone help me with the fuel mix ratio and also looking for a manual. Thanks

 

[F_R]

Not finding that model number. Can you post a picture so maybe we can identify it? In the meantime, run 16:1. It won't hurt it.

 

[F_R]

Ah, I found it. That is the Tecumseh engine model number. Used on 1969 Sears model 217-58520.

Don't know for sure, but it probably was specified for 50:1, but if it were mine I wouldn't run it at less than 24:1, using chainsaw oil. That motor runs much hotter than water cooled ones. It was originally designed to be used on a chainsaw at 16:1

 

[Aquafix]

Thank you for the help.