1977 1978 1979 - 1985 Yamaha Mariner 20" Lower Unit 40 50 HP 1 YEAR WARRANTY✨

• 20 Inch Driveshaft  
• Fully resealed 
• Extended Warranty with exchange of a spinning core(see below for more info)

• Shifts and spins smoothly without binding
• Shafts checked for straightness
• Driveshaft splines good condition with little to no wear
• Gears & clutch good condition with only light wear 
• Freshwater Condition
• New Impeller
• Fully Resealed & Pressure checked to 12 PSI

Driveshaft splines: 14

Propeller shaft splines: 13

Driveshaft length from the top of the water pump to top of the shaft: 20-15/16"

Please add oil before use. This unit is shipped empty. 

This lower unit qualifies for a 1 year warranty.  The warranty is validated by your core.  In order to qualify for this, you must send in that core.  Both shafts must spin and it must be complete.  We will send a label for you to return your core in our box after receipt of the unit you’ve purchased.  If you do not have a spinning core, you may call in after your purchase and buy the 1 year warranty for 10% of the purchase price.  If you do not return a core or purchase a warranty, this unit will be sold with a 45 day warranty and nothing more or less.

Location: Southcentral Outboards, Altamont, Illinois

We have provided this cross-reference with the resources we have available in regards to fitment. This most likely will not fit every model for the years and horsepowers we have listed. We urge you to make sure this is the exact item you need by matching the part number to what is required for your motor. If you need help doing so, please contact us prior to purchasing and we would be happy to help!