Mercury MERCRUISER, Service Manual, Page: 471 / 566

4. Place a finger over the open end of the clear hose before removing the hose from the water.
5. Coil the excess clear hose into the boat bilge. Keep the coil of hose below the waterline.
6. Keeping the 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 your 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.
Typical model with Emissions Control
a - Waterline
b - Top of exhaust elbow
c - Waterline to top of exhaust elbow
measurement
d - Clear hose
e - Weight
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 hose is 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 any 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 your finger over the hose, and
lift the open end until it is at the top of the exhaust elbow.
7. Slowly take your finger off of the end of the hose to let the water level stabilize. The water will seek the level of the water in
the muffler. Keep the hose close to the exhaust elbow and as vertical as possible.
a
e
b
d
d
c
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Important Information
90-8M0099748 eng DECEMBER 2015 © 2016 Mercury Marine Page 7A-9