Zzr 1100D running rough.

[Chris Fullwood]

Had my 97 zzr 1100D for nearly two years, no problems apart from routine servicing and part replacements, bike standing for past three months,on restart she was running on three, replaced plugs, one of which was oily, number 4, on restart engine sounded terrible, kind of clattering, pot four definitely not firing, has been suggested that oil ring on piston four has gone. Any other suggestions most welcomed. Made a twenty second video but haven't succeeded in posting it as yet, thanks. Chris.

[RideWithStyles]

Spark plug lead / coil pack.

 There are old school ways to figure this out. Feel or better yet a thermo sensor. 
the lead / cylinder will be cooler than the others if its gone. Also the feel of the vibration on the very particular cylinder if your very sensitive to that sort of thing.

when the bike is on 3 cylinder, you could just unplug a coil lead, if it goes to two then that one is ok, if it stays three its that one.

[megaross]

If a cylinder isn't firing your plug will appear damp when pulled.

 

3 months standing?

 

Water will settle to the bottom of the tank when I bike sits then the bike runs like microwaved shit and the owner thinks their bike is a write off, seen it a few times over the years. I'd be draining the tank and trying some fresh juice first.

 

Coil pack or lead are likely contenders here too, give a good inspection for cracks then pull the plug, ground it and crank to check for spark. Good clean white spark, not flaccid orange spark.

 

If you had a ring going it would've become obvious before you laid it up, rings can seize up a bit when stood but unheard of in 3 months unless it was stored on the Titanic. You could compression test but I'd put a pair of tyres on it being nothing to do with compression based on what you've said so far.

 

If it was oil in a good quantity it might be your valve stem seal leaking but again, unlikely unless your bike has a shit ton of miles.

 

Basically - check fuel and spark.