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WARRANTY INFORMATION
PARTS INFORMATION
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Sales Manager
Corrosion Prevention and Maintenance
Models
ALL MerCruiser, Outboard and Jet Drive Products
Drive Corrosion
The prevention of marine corrosion can be a challenge for boat owners. However, corrosion
damage is almost always controllable; it just requires knowledge of what causes corrosion,
and the proper maintenance steps that must be taken to protect the product.
Over the years, Mercury has published several guides and manuals to educate dealers and
boat owners about corrosion, and what steps should be taken to prevent corrosion from
causing significant and costly damage to submerged drive components. All Mercury dealers
should be familiar with these publications, understand the primary causes of corrosion, and
what to do to prevent marine corrosion in all types of boating environments. During the pre-
delivery inspection process with the boat owner, review the proper maintenance activities
that are needed to ensure that the boat and sterndrive are properly protected from corrosion.
Also, we encourage you to review the contents of the Mercury Corrosion Protection Guide
with them, and give them a copy to take home. This guide is available to you at no charge
by ordering 90-881813 01 (Mercury branding) or 90-809844 01 (Quicksilver branding).
If a boat owner has a complaint about corrosion damage, please perform the necessary in-
spection and testing procedures to identify the source of the corrosion (see enclosed 3 page
Corrosion Test Data Sheet that can assist you in this effort). As always, our dealer technical
support team is available to provide technical assistance in the diagnosis and correction of
corrosion. Contact MerCruiser technical support at 405-743-6555 or outboard technical
support at 920-929-5884.
THE INFORMATION IN THIS DOCUMENT IS CONFIDENTIAL AND PROTECTED BY COPYRIGHT AND IS THE PROPERTY OF MERCURY MARINE.
This document is provided for the sole and exclusive use of the original recipient as prescribed by Mercury Marine and may not be distributed or
copied, digitally or otherwise, without the prior written consent of Mercury Marine.
2002-06 APRIL 2002
SERVICE INFORMATION
Accounting
Service Manager
Printed in U.S.A. -
2002, Mercury Marine
Bulletin No. 2002-06
Technician
Parts Manager
Page 1 of 16
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Summary of Contents for Mercury MerCruiser Alpha
- Page 1 WARRANTY INFORMATION SERVICE INFORMATION Bulletin No. 2002-06 PARTS INFORMATION Circulate to: Sales Manager Accounting Service Manager Technician Parts Manager Corrosion Prevention and Maintenance Models ALL MerCruiser, Outboard and Jet Drive Products Drive Corrosion The prevention of marine corrosion can be a challenge for boat owners. However, corrosion damage is almost always controllable;...
- Page 2 CORROSION PREVENTION AND MAINTENANCE What is Corrosion Types of Marine Corrosion; Metal parts under water are primarily subjected to two basic types of corrosion: 1) Galvanic Corrosion 2) Stray Current Corrosion. 1) Galvanic corrosion: Galvanic Corrosion is an electrochemical reaction between two or more different (or “dissimilar”) metals.
- Page 3 1. Sacrificial Anodes: Come in both aluminum (for use in fresh, Brackish and saltwater) and magnesium (for use in fresh water only). 2. MerCathode: Comes standard on all Bravo product and is available in a kit for Alpha product. 3. Transom Mounted Anode: Connected to the current MerCathode for additional anodic protection.
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Page 4: Test Equipment
(91-854009A3) along with the Quicksilver Reference Electrode (91-76675T1). A copy of the 3 page corrosion data sheet is included with this bulletin to be completed and re- turned to the appropriate service group. Alpha Bravo I, II Bravo III Fresh Water Conditions... - Page 5 CORROSION PREVENTION AND MAINTENANCE The procedures listed below will be located in the publications following. 1. Corrosion Protection, Testing and Trouble Shooting 2. Drive Unit Continuity Test 3. Hull Potential Testing 4. Stray Current Corrosion 5. Crevice Corrosion 6. The effect of water velocity on corrosion rates 7.
- Page 6 CORROSION PREVENTION AND MAINTENANCE Step by Step Procedures when checking a boat for a Corrosion Problem at the Location where the boat is normally moored Tools Required: 1) Digital Multi-meter (VOA)(volt/ohm/amp) (91-854009A 3) 2) Quicksilver Reference Electrode tester (91-76675T1) The first five things to check before performing any test: 1) If equipped with shore power, unplug the shore power.
- Page 7 CORROSION PREVENTION AND MAINTENANCE Step 3) Measuring Hull Potential 1) The boat must be in the water where the boat is moored when performing this test (with- out being operated) for at least 8 hours before performing the test. This is necessary to allow the MerCathode System and/or the sacrificial anodes to polarize the water mole- cules in direct contact with the drive unit.
- Page 8 CORROSION PREVENTION AND MAINTENANCE Step 5) Symptoms of hull potential reading too low are: a) Too much (cathode) such as stainless steel. b) Loss of continuity between drive components and ground. c) Sacrificial anodes more than 50% consumed or painted or inactive. d) MerCathode reference wire or anode plate painted over.
- Page 9 CORROSION PREVENTION AND MAINTENANCE Step 6) Symptoms of hull potential reading too high are: a) Paint blistering and falling off. b) Pitting of aluminum on the drive. Excessive voltage causes hydrogen to be formed at the surface of the metal “blow- ing”...
- Page 10 CORROSION PREVENTION AND MAINTENANCE f) Faulty MerCathode Controller. Check output of the controller. If the hull potential indicates overprotection, remove the reference electrode lead from the controller. If the controller is “off” (no impressed current called for) the volt- age between the negative (black) and the anode should be less than (one volt). If your digital multi-meter can read amperage, with the reference electrode disconnected, the amperage between the negative on the controller and the anode terminal should be less than one milliamp.
- Page 11 CORROSION PREVENTION AND MAINTENANCE Out of Water Resistance Check A Digital Multi-Meter such as the Mercury DMT2000A (91-854009A 3), a Fluke Digital Multi- Meter or a Radio Shack Digital Multi-Meter or equivalent must be used for this test. (a) Meter setting on low ohm range (2 ohm). (b) Connect the Black meter lead from the (COM) port on the meter to the drive unit Trim Tab or the drive shaft housing Cavitation Plate Anode.
- Page 12 7.) If the reading goes to infinity the diode is shorted and the Galvanic Isolator requires replacement. Newly developed Anode kits for Current MerCruiser Sterndrives The following kits include all anodes required to replace every anode on the Alpha and Bra- vo drives and transoms. 888756A 1...
- Page 13 CORROSION PREVENTION AND MAINTENANCE Corrosion Test Data Sheet Initial Test Data Form Date of Test : Month Year Dealer Name Dealer Number Customer Name Address Telephone Number (____)____________________________ Address where the boat is Moored Boat Manufacturer Boat Model Type of Installation: Single ( Dual ( Triple (...
- Page 14 CORROSION PREVENTION AND MAINTENANCE MerCathode System Type: Boat Transom Mounted ( ) or Gimbal Housing Mounted ( Water Type: Fresh ( Brackish ( Salt ( Water Velocity: (speed of movement) ( ____ mph) Propeller Type: Aluminum ( Stainless ( Boat Equipped with Trim Tabs: Yes ( No ( If so what type:...
- Page 15 CORROSION PREVENTION AND MAINTENANCE Continuity Test: Millivolt Reading, the boat must be in the water for this test. 1. Set the Digital Multimeter on the 0-2 volt (0-2000 millivolts) scale. 2. Connect the negative (black) meter lead to the negative (–) battery terminal. 3.
- Page 16 CORROSION PREVENTION AND MAINTENANCE Has a Stray Current Check been done? Yes ( No ( If so, what was the reading taken: Have pictures been taken? Yes ( No ( The Locality of the Corrosion: ) All under water power package components. ) Gear Housing ) Drive Shaft Housing ) Bell Housing...
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drain & refill outdrive lower unit 1994 Mercruiser Alpha One