Um, ALL cars/trucks/SUV's have spark plugs.
What a stupid question.
I have a 2000, I'm sure they are the same..take the four bolts off the top cover (the one that says 2.4 or whatever) and carefully lift the piece out...there are plastic and rubber boots attaching the cover to the plugs.
On the oil pan.
You need a six extension and a spark plug socket with a rubber stop inside. The spark plugs are located on top of the engine. They are about 4 inchs inside the head. Using the extenion put the socket with the rubber piece inside which will grip the plugs when they are unscrewed allowing you to remove the plugs. When installing use the same socket but press the plugs inside the socket so they are being gripped which will you to slowing lower them inside the head with the extension and get them started. I suggest you start them by hand.
fixed it was spark plug wires.
To locate and change the the (4) spark plugs on a 2004 Hyundai 2.4L 4 cylinder engine: Remove the (4) 12mm bolts from the decorative plasitc engine cover. Remove plastic cover from engine and place it off to the side out of your way. Standing in front of the car, the (4) spark plugs are located laterally (left to right) in the recessed area underneath where the plastic engine cover was removed. Note: This engine has (2) coils....They are located above spark plugs number (2) and (3) from left to right. Starting with the fist spark plug on the left: Remove the spark plug cable by pulling straight up on the insullated connector. Using a spark plug socket, remove the old spark plug and install a new one in it's place. To access the second spark plug from the left, remove the electrical connector and the spark plug cable wire from coil number (1) and then remove the (2) 12mm bolts that secure the coil to the engine. Spark plug number (2) is located directly under the coil. Lift the coil straight up removing the insulated connector from spark plug number (2). Using a spark plug socket, remove old spark and install a new one in it's place. Repeat same procedures for spark plugs number (3) and (4).
maybe some water stuck in the cylinders
Check plugs and plug wires---worked for mine.
Johnson outboards, model RDS-24L, would be a 1962 year model, 40 hp. the boat motor is a 50 hp.
i think you disconnect one of the plug wires or you need to change one of them . It could be the oxygen sensor, valves, plug wires or a sticking fuel injector. You'll have to get a little more specific. If it ran well BEFORE changing the plugs and now it doesn't, perhaps 2 of the plug wires have been cross-connected.