Propeller Selection - Mercury 9.9 EH Manual

IMPORTANT: Please follow the instructions below:
• Hydrogen gas is generated when charging a battery. Keep the
battery in a well‑ventilated area during charging. Remove the
battery from the boat; this will protect your hull and interior
from damage. Electric sparks, cigarette smoking, and other
sources of fire must be avoided in the charging area to prevent
explosion of the battery.
• The battery fluid (electrolyte) contains sulfuric acid. If
electrolyte is spilled on the skin or clothes, wash with plenty
of water and consult a medical doctor. Always use safety
glasses and rubber gloves when handling the battery.

Propeller Selection

The propeller supplied with your outboard provides the best overall
performance under average operating conditions.
Propeller must be selected so that the engine rpm when cruising
with a wide‑open throttle is within the recommended range.
Model
9.9
15/18
If changing conditions cause the rpm to drop below the
recommended range, such as warmer, more humid weather,
operation at higher elevations, increased boat load, or a dirty boat
bottom/gercase, a propeller change or cleaning may be required
to maintain performance and ensure the outboard's durability.
Check full‑throttle rpm, using an accurate tachometer, with the
engine trimmed out to a balanced‑steering condition (steering
effort equal in both directions) without causing the propeller to
break loose.
PROPELLER TABLE
A propeller must be selected so that the engine rpm measured at
wide open throttle while cruising is within the recommended
range. Refer to Accessories - Propeller Table of this manual.
INSTALLATION
Wide‑open throttle rpm range
4500‑5300 rpm
5200‑5800 rpm
48