Table of Contents
Advertisement
7.
Rotate the flywheel so the piston is at TDC.
8.
Complete the cylinder leak down test.
9.
Proceed with the succeeding firing order cylinder TDC and complete the cylinder leak down test.
10. Complete the procedure in sequence on the remain cylinders.
Analysis
Due to standard engine tolerances and engine wear, no cylinder will maintain a 0% of leakage. It is important only that cylinders
have somewhat consistent reading between them. Differences of 15 to 30% indicate excessive leakage. Larger engines tend to
have a larger percentage of cylinder leakage than smaller engines.
If excessive leakage is present, first check that the piston is at top dead center of its compression stroke. Leakage will naturally
occur if the exhaust or intake valve is open.
To determine the cause of high percentage leaks, you must locate where the air is escaping from. Listen for air escaping
through the intake, adjacent spark plug holes, exhaust pipe, and crankcase oil fill plug. Use the following table to aid in locating
the source of cylinder leakage.
Painting Procedures
Continuous exposure to airborne particles such as chemical vapors, dust, or spray can cause serious injury or death. Ensure
that the work area is properly ventilated and wear protective eyeware, clothing, and respirators.
Propellers
1.
Sand the entire area to be painted with 3M 120 Regalite Polycut or coarse Scotch‑Brite disc or belts.
2.
Feather edges of all broken paint edges. Try not to sand through the primer.
3.
Clean the surface to be painted using PPG Industries DX330 Wax and Grease Remover or equivalent (Xylene or M.E.K.).
4.
If bare metal has been exposed, use Mercury/Quicksilver Light Gray Primer.
5.
Allow a minimum of one hour dry time and no more than one week before applying the finish coat.
6.
Apply the finish coat using Mercury/Quicksilver EDP Propeller Black.
Gear Housing
The following procedures should be used in refinishing gear housings. This procedure will provide the most durable paint
system available in the field. The materials recommended are of high quality and approximate marine requirements. The
following procedure will provide a repaint job that compares with a properly applied factory paint finish. It is recommended the
listed materials be purchased from a local Ditzler Automotive Finish Supply Outlet. The minimum package quantity of each
material shown following is sufficient to refinish several gear housings.
1.
Wash the gear housing with a muriatic acid base cleaner to remove any type of marine growth, and rinse with water.
2.
Wash the gear housing with soap and water. Rinse with clean water.
3.
Sand blistered area with 3M 180 grit sandpaper or P180 Gold Film Disc to remove paint blisters only. Feather edge all
broken paint edges.
4.
Clean gear housing thoroughly with DX‑330 Wax and Grease Remover.
5.
Spot repair surfaces where bare metal is exposed with DX‑503 Alodine Treatment.
IMPORTANT: Do not use aerosol spray paints as the paint will not properly adhere to the surface, nor will the coating be
sufficiently thick to resist future paint blistering.
6.
Mix Epoxy Chromate Primer DP‑90LF with equal part catalyst DP‑402LF per the manufacturer's instructions. Allow proper
induction period for permeation of the epoxy primer and catalyst.
7.
Allow a minimum of one hour drying time and no more than one week before the top coat application.
8.
Use Ditzler Urethane DU9300 for Mercury Black, DU34334 for Mariner Grey, DU35466 for Force Charcoal, DU33414M for
Sea Ray White, and DFHS 37372H for Verado Silver. Catalyze all five colors with Ditzler DU5 catalyst mixed 1:1 ratio.
Reduce with solvents per Ditzler label.
90-8M0105568 eng MARCH 2016
Air Escaping From
Air induction
Exhaust system
Oil fill plug
Adjacent cylinder
WARNING
!
© 2016 Mercury Marine
General Information
Possible Location
Intake valve
Exhaust valve
Piston/rings
Head gasket
Page 1C-15
Advertisement
Chapters
Table of Contents
Troubleshooting
