Mercury 15 EFI FourStroke, Service Manual

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Lubricant, Sealant, Adhesives
Tube Ref No. Description Where Used Part No.
25
Liquid Neoprene All ring terminal connections 92- 25711 3
Special Tools
Cylinder Leakage Tester Snap‑On EEPV309A
11604
Aids in checking cylinder leakdown.
CDS G3 Diagnostic Tool Kit 8M0114141
60575
Interfaces CDS G3 software to SmartCraft network.
NOTE: This kit includes download instructions and a license key.
CDS G3 Cable Kit 8M0137534
65167
Allows the use of the CDS G3 diagnostic tool on small EFI Fourstroke outboard
engines.
Conditions Affecting Performance
Bottom of Boat
For maximum speed, a boat bottom should be nearly a flat plane where it contacts the water and particularly straight and
smooth in fore and aft direction.
•
Hook:
Exists when bottom is concave in fore and aft direction when viewed from the side. When boat is planing, hook
causes more lift on bottom near transom and allows bow to drop, thus greatly increasing wetted surface and reducing boat
speed. Hook frequently is caused by supporting boat too far ahead of transom while hauling on a trailer or during storage.
•
Rocker:
The reverse of hook and much less common. Rocker exists if bottom is convex in fore and aft direction when
viewed from the side, and boat has strong tendency to porpoise.
•
Surface roughness:
Moss, barnacles, etc., on boat or corrosion of outboard's gear housing increase skin friction and
cause speed loss. Clean surfaces when necessary.
Cavitation
Cavitation occurs when water flow cannot follow the contour of a fast‑moving underwater object, such as a gear housing or a
propeller. Cavitation increases propeller speed while reducing boat speed. Cavitation can seriously erode the surface of the
gear housing or the propeller. Common causes of cavitation are:
•
Weeds or other debris snagged on the propeller
• Bent propeller blade
• Raised burrs or sharp edges on the propeller
General Troubleshooting
Page 1E-2 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017