Mercury 8.1S Horizon, Product Applications Manual

Page: 92 / 163

Exhaust System
90-863758060 AUGUST 2006 Page 6A-23
IMPORTANT: On engines equipped with more than one exhaust elbow, perform the
exhaust elbow waterline height measurement on the side that sits lower in the water.
2. Put the weighted end of the clear hose over the side of the boat (port or starboard) that
is sitting lower in the water.
3. Submerge the clear hose until completely filled with water.
4. Place a finger over the open end of the clear hose before removing it from the water.
5. Coil the excess clear hose into the bottom of the boat bilge. Keep the coil of clear hose
below the waterline.
6. Keeping the clear hose in line with the engine's exhaust elbow, lift the end of the clear
hose up to the highest point of the exhaust elbow.
7. Slowly take the finger off of the end of the clear hose to let the water level stabilize. The
water will seek the level of the water outside of the boat. Keep the clear hose close to
the exhaust elbow and as vertical as possible.
b
c
a
8340
e
d
9142
a - Waterline
b - Top of exhaust elbow
c - Clear hose
d - Weight
e - Measurement, waterline to top of
exhaust elbow
Clear Hose Measurement Method From Seacock or Muffler Drain
IMPORTANT: Measure the exhaust elbow height to the waterline inside of the water lift
muffler (instead of the water line outside of the boat) on applications so equipped.
IMPORTANT: The engine must have been operated previously to fill the muffler with water.
IMPORTANT: On engines equipped with more than one exhaust elbow, perform the
exhaust elbow waterline height measurement on the side that sits lower in the water.
1. Attach a clear hose to the muffler drain point or seacock drain point.
2. Start the engine to fill the muffler and hose.
3. If attached to the seacock drain, open the seacock.
4. Route the remainder of the hose toward the engine's exhaust manifold and elbow.
Ensure that this open end section of the hose is as vertical as possible from the boat's
bilge to the top of the exhaust elbow.
5. Coil excess hose in the bilge of the boat, keeping it below the water line.
6. Lower the open end of the hose and siphon water until it starts to come out of the hose.
Put a finger over the hose and lift open end until it is at the top of the exhaust elbow.