9.9 merc outboard serial # 114058 what year is it ?

Product Line Year H.P. Model Number Model Description MERCURY 1978 115 1115628 MERC 115

available from any merc outboard service shop
if there is none close , the kit may be generic so mariner pump may fit
talk with outboard shop spares

I can't find that exact # but -
The date on some models is a two digit number in a square box on the lower right side of the serial # tag to the right the letters CE.

Merc 1500 (V-6) Serial numbers 5129480 though 5503246 are 1979. 150hp.

It's a Merc 45 from 1978. Serial numbers 4869518 thru 5270783 are 1978.

It is a 1973, Merc 500. Serial numbers 3478003 though 3816307 are 1973.

According to i-Boats, "Nothing in the Mercury Mariner Outboard engine model numbers or serial numbers provides year information directly.
The first serial number sold in a year becomes the beginning serial number. Serial numbers between that year's beginning serial number and the next fall into the same year. Search for your engine horsepower on the Mercury Mariner serial number year chart located here to find the beginning serial number for the range that includes your engine." Your other option is to take the serial number to an authorized Merc marine eager and they can look it up for you.

Try here,
Outboard Motors Boat Parts Marine Engines Inboard Boat Motor

call mercury outboard they can tell you the answer to your question