Q & A — January 2002
By Capt. Ken Kreisler
2: Galvanic Corrosion, Misfiring Outboard, and more
While checking the
oil on my stern drive’s engine, I noticed what appears to be sludge
on the dipstick. What is going on, and what can I do about it? C.B.,
If the problem recurs within the specified change interval, you may have a more serious problem, including a cracked head or block or defective cylinder head gasket.
does galvanic corrosion occur in a diesel engine’s cooling system?
V.S., via e-mail
But that’s not the only way galvanic corrosion can occur here. It also can be the result of an exterior source. To help prevent this type of situation, the electrical system must be designed so that all grounds are tight and free from corrosion. Some of the more common trouble spots are improperly grounded electrical components and a corroded ground strap connection. Regular checks and cleaning will eliminate any potential problems.
Aluminum parts of newer engines are more susceptible to electrolytic corrosion–the metal requires only about one-half the electrical potential as iron to produce the same damaging effect–so owners of such engines need to be more watchful of this problem.
My carbureted outboard
engine has begun to misfire at idle. What should I check? C.A.,
Also check all spark plug wires for corrosion or poor contact and the condition of your coil and points and condenser if so equipped.
Need help with a maintenance problem? Write to Maintenance Q & A, Power & Motoryacht, 260 Madison Ave., 8th Fl., New York, NY 10016. Fax: (917) 256-2282. e-mail: firstname.lastname@example.org. No phone calls, please.
This article originally appeared in the January 2003 issue of Power & Motoryacht magazine.