What year is the boat?
Sounds like you received an Alpha engine set_up vs a needed Bravo set_up.
CPO= Certified Pre-Owned RM= Remanufactured.
MERCRUISER part/Model Number 865108R26 = 350 Mag MPI Alpha Engine Only, Multi‑Port Fuel‑Injected using Gen II Cool Fuel, Certified Pre‑Owned with a 1‑Year Factory Limited Warranty 300 HP Sterndrive Engine (s/n 0M600000 and up) Mercury Branded
Since you have a bravo stern drive, I’d say technically speaking, someone ordered you the wrong engine combination for the setup you had which in most cases make installation a bit harder to do but with the less parts the CPO’s say they come with after rebuild, it probably wasn’t much of an issue because they most likely used a bunch of the original parts from the first engine which isn’t an issue really, just pointing it for your benefit of knowing what may have happened during ordering/installing.
I think they should have ordered either part/ Model number listed below I believe depending on year of boat/original engine.
865108R25 350 Mag MPI Bravo Engine Only, Multi‑Port Fuel‑Injected using Gen II Cool Fuel, Certified Pre‑Owned with a 1‑Year Factory Limited Warranty 300 HP Sterndrive Engine (s/n 0M600000‑0W059999) 865108R24 350 Mag MPI Bravo Engine Only, Multi‑Port Fuel‑Injected using Gen 3 Cool Fuel, Certified Pre‑Owned with a 1‑Year Factory Limited Warranty 300 HP Sterndrive Engine (s/n 0W060000 and up)
Mercury Branded
CPO MERCRUISER ENGINE-350 MAG BRAVO EC
Mercury Branded
8M0060615 350 MAG MPI Bravo Engine Only. Multi‑Port Fuel‑Injected with emissions control catalyst system Certified Pre‑Owned with a 1‑Year Factory Limited Warranty 300 HP Sterndrive Engine (s/n 1A623185 and up) Mercury Branded
2013 Remanufactured Product Guide
For info guidance of all the above, here’s the link for future references,
https://kipdf.com/engine-break-in-p...-engine-headers_5adc39de7f8b9a127e8b459f.html
The info for this case is about halfway down the page.