KDracing
12-17-2008, 03:28 PM
2003 400ex engine all stock, engine was running rough so changed the plug, now enigne runs great. when i pulled the old plug it was full of carbon, and fit the definition of carbon fouled according the the shop manual, now the shop manual says it could be one of a few things.
1) running rich mixture
2) prolonged idleing
3) faulty ignition control module
4) spark plug heat range too cold
5) clogged air filter
6) poor compression
i am pretty sure it is not #6, engine has plenty of power; #5, almost brand new UNI foam filter; #2, only really idles when warming up, and a minute or two after hard ride
so my question is how can i figure out which one of the remaining options is what caused my fouled plug and how to fix it????
# 1,3,4???
1) running rich mixture
2) prolonged idleing
3) faulty ignition control module
4) spark plug heat range too cold
5) clogged air filter
6) poor compression
i am pretty sure it is not #6, engine has plenty of power; #5, almost brand new UNI foam filter; #2, only really idles when warming up, and a minute or two after hard ride
so my question is how can i figure out which one of the remaining options is what caused my fouled plug and how to fix it????
# 1,3,4???