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  #4   IP: 172.95.97.58
Old 06-08-2018, 10:54 AM
Dave Neptune Dave Neptune is offline
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Things seem a bit backwards as far as your plug temps. If #4 is fouling it should be the "coolest" to the touch.

Before doing to much fiddling check you spark at the # 4 plug or if it is difficult any other plug will be OK. You should see a crisp blue flash, if it is pale or yellowish no good.

And if the spark is good start it and try leaning the idle by "opening" the idle air screw about a half of a turn and see if the idle becomes smoother. The average setting on most of these beasties is 1 1/2 turns off the seat. Remember that the screw adjusts the amount of air not fuel so out is lean and in is rich.

Another important and often over looked part of the ignition system are the "spark plug boots" the "BOOT" part needs to fit snug on the plug ceramic and should have no cracks. The boot ceramic relationship is what controls the heat radiated by the plug so they are important as far a good plug temps. A good idea is to coat the inside of the boot with some dielectric grease to aid in not sticking, tears in the boot and good contact for the insulating job the boot does to maintain good plug temps.

Dave Neptune
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