one at a time
The 1999 model, 90 hp Mercury outboard requires an NGK BUHW-2 spark plug, standard plug wires are acceptable.
The spark plug locations are all on the same side of the engine. They are in the side of the head, where the plug wires are connected.
One at a time.
If you open the hood and can see only 3 spark plug wires: you have 6 cylinder engine. Otherwise you have 4 cylinder engine (you can see only 4 spark plug wires).
To replace spark plug wires on a 3300 Oldsmobile engine, open the hood and remove the wires from the end of the engine. The number of spark plug wires most often corresponds to the number of cylinders your engine has.
Spark Plug wires connected incorrectly, or engine is out of time.Spark Plug wires connected incorrectly, or engine is out of time.
Changing the spark plug wires in your 1999 Mercedes-Benz is quite simple. The spark plug wires simply lift off. The new spark plug wires can be pushed onto the spark plug. It is best to change one wire at a time.
There are no spark plug wires. Each spark plug has its own coil and the spark plug attaches to the coil directly. To access the coil and plug, you need to remove the black plate on the top center of the engine (4-6 torx screws, I believe).
A diesel engine doesn't have spark plugs or spark plug wires.
You should have C.O.P. ( coil on plug) there are no wires.
You need to replace your spark plug wires!! You can check this by spraying water on your spark plug wires when it is dark. Then start your engine and you should see the wires arc and your engine will be running rough just as it does when it rains or after a rain. Good Luck
Some don't have wires, the coils are mounted direct to the spark plugs. Some have a dual spark plug design where the plug mounted coil also sparks another spark plug on the other side of the engine. Removint these spark plug wires will still allow the engine to run but will eventually ruin the coils. And the third type will not run with out wires.