Mercury Outboard 115hp Temperature Sender Sensor 78799 1 78799 2 100hp 125hp 3hp There will be 8 Splines

There will be 8 Splines if it is this style of gearcase

Basically the parts manual indicating one thing and the actual part having another

they changed the designs a few times

0L 4cyl applications for Pre-Alpha/R/MR/ALPHA ONE Gen 1

Mercury Outboard 115hp Temperature Sender Sensor 78799 1 78799 2 100hp 125hp 3hp There will be 8 SplinesRemoved from a Mercury Outboard 115hp (S N OG240680) Inline 4 cylinder 2 Stroke Part #'s Temperature Sender: 78799 1,(Ring Terminal) may also work for this (78799 2) Item Condition and Notes: Good Working Condition Please Inspect Pictures for condition Yours should look like this one. Please ask if you are unsure if this part will work for you. Please send model and serial number. You will receive what is in the pictures. Please inspect pictures