Plug electrode colours

[c4cpa]

Cars felt a bit sluggish for a while so i thought i'd check the plugs last sun,

First 3 didn't look to bad and the fourth had a small carbon build up, however all the electrodes had a kind of browny tinge to them. I've been told that this would indicate a weak spark, is this right?
If this is the case would changing the plugs and leads cure it or does it indicate the car needs tuning?

Just wanted to know cos with the japshow at pod on sunday i don't want to kill my car on the strip.

Cheers,
Col.

 

[geetee]

If ur mixture is perfect the whole time you should expect to see a mid brown electrode and no major deposits. When I used to tune 2 stroke motorbikes we always aimed for a Rich Tea coloured plug after a wide open throttle acceleration through the gears - then kill the motor whilst on full throttle still accelerating in 4th or 5th

White indicates - weak mixture / overheating

Black (which is very common on the Pulsar) rich.

If you have deposits on only one plug then that cylinder probably isn't combusting fully for some reason. I'd be inclined to get down to Halfords and buy a compression tester and use it. At least it will set ur mind at rest if nothing else.

Otherwise it could be a dodgy plug lead or cap or problem in the dizzy causing a poor spark - this could also be caused by the plug gap.

It could also be caused by a problem with the injector - i.e. stuck open or otherwise overfuelling.

Start with the simple things 1st !

CHeers
GeeTee 8)

 

[c4cpa]

Cheers for that mate, i'm off to halfords now !!

 

[Shaun]

Hi guy's,sorry to but in,do you use an octane boost :?: ,as this tends to put a 'browny tinge' on the plugs :!: So could just be simply that :!:

Hope this helps.

 

[memski]

Cars felt a bit sluggish for a while so i thought i'd check the plugs last sun,

Maybe the hotter weather has had an effect on your car's performance? Just a thought...