My rear plug in my 2005 Electra Glide Classic is burning up faster.It is backfiring and burping alot but seems to run ok, just is that the rear plug crystalizes or burns up with less than a thousand miles. It is fuel injected. Also my other bike is a 2007 Street Bob upgraded to a screaming eagle (103) and is it ok to run the splitfire plug or stick with the regular plug?

 

I would check for intake manifold leaks/timing/mapping

 

test

 

What's the oil consumption like? There was a problem in 2005 with valve seals.