I have a 55 plate 1200c and last Monday it developed a really bad rattle and I lost all power and I pulled the clutch in and hit the kill switch the rattle is coming from my front cylinder I've had both rocker covers off and it looks and acts like it should.
im a bit lost as to what to look at next I had myself convinced it was pushrods but everything is good on the top end just scratching my head now

 

Next step it to remove the head or use a borescope down the spark plug hole.

 

Have ordered the borescope cheers for that

 

Excuse my ignorance, but wtf is a 55 plate?
What year is the bike and what is the mileage? (under warranty?)
How long have you owned it?

 

A 55plate denotes the registration as being a late 2005 early 2006 its just the way england registers vehicles.
i have owned it since September 17 it has 18300 miles on it