HELP why has my rotor arm burnt to a crisp

[denniselbows]

can anyone tell me why my rotor arm has burnt out like this.

i have had a miss fire at wot for a couple of weeks now and only just had chance to look at it. i feel quite lucky that i have found this before anything went bang. and i did over 400 miles around cornwall on a hol last week. my car has a mrc chip boosting at around 1.4-1.5 bar, ht leads were replaced a couple months ago (magnecor kv85 ) standard coil at the moment but have got a 034 high out put on the spare bed but am really not sure is it a good idea to fit it or not now seeing as what i have just found.
i have all ways had concerns that the resistor could burn out with a high out put coil.

[S2central.net]

Personally I wouldn't bother with an uprated coil on the 3B. Its weakest link is that spark hop inside the dissy cap can cause catastophic pre-ignition and bend a conrod (or two)... A higher energy coil just increases the chances of that.

1 - Make certain the dissy is timed correctly

2 - Renew the rotor arm - ensure its the correct narrow tipped version - a bigger tip is BAD... Search out a thread here on the correct tip dimension and/or a neat way to modify an alternative rotor arm that allegedly reduces chances of spark hop

3 - Renew the dissy cap as well

4 - Check you have the right single electrode plugs and that they are gapped correctly

5 - Maybe worth a quick impedance check across both sides of the coil as well

WIth everything renewed and checked I would run that for a while and monitor how long it takes for things to degrade...

[denniselbows]

thanks paul for the pointer by the way