Plug fouling

[odie1962]

I have a 2002 FDL which has the 88" twin cam. Problem is I have a problem with the back plug fouling, Not often but about every 6 months or so. Front plug looks fine but the back one is all black and covered with suet. causing backfires and such, any ideas?

 

[jaxdwg]

If the plug has a shiney look when you take it out, rather than flat-black sooty, that is an indication of oil consumption----shiney is oil, flat is fuel