quote Chris_P:
16:1 for the 7.5hp
24:1 for the 18hp
24:1 for the 18hp
Exakery! The 5.5 and 7.5 horse motors have bronze sleeve type (friction) bearings on the crank and rods which need the extra oil while the ten horse use a combination of friction and needle/roller bearings while the eighteen horse and larger used needles and rollers throughout. Using a good brand of TCW III rated marine oil at the proper ratio instead of the motor oil suggested back in the fifties will help ensure the motor will still be running for your grandkids to enjoy!
