[b]changing plugs[/b]

[hitthebricks]

Last year I changed the plugs on my 2001, 200 Optimax and found the motor still wouldn't idle smoothly, seemed to have a slight miss. When I told my bro in law about this he asked if I made sure the plugs were lined up with the injectors in each cylinder. Is this a bunch of malarky or is there some truth to this?

Thanks HTB

[2thepointsetters]

Spark plug indexing is done on high perfomance equipment.In order to do it you have to take the head off and see where each plug ends up and add small shims so they line up perfectly when tightened to the correct torque. There is no reason why you would do that to a normal motor it takes a long time.

[boatfixer]

There is a much easier way to index. Mark the plug with a sharpie prior to installation. As to whether or not its necessary...

Now, which plugs did you put in there? It likely came with NGK PZFR5G which is a platinum electrode plug. In 2003 Merc switched to a NGK IZFR5G which is an Iridium electrode plug which now supercedes the platinum. The Iridium plug is suposed to burn cleaner at an idle and reduce fouling.

[hitthebricks]

Boatfixer, Your method is what the inlaw was talking about and not sure which plug I installed. Can I use the irradium plug in my motor.

[boatfixer]

yup