still got a misfire ... help

[Batesy58]

Hi I have a misfire on a 172 I've changed the coil twice leads and plugs .... When I take no.1 out its the only 1 that sounds the same so i no I have a problem with number 1 but if I put it back in it sound like its on 3.5 cylinders ... Any ideas? Thanks Nathan

 

[MicKPM]

Have you checked to see if there is any water/oil in the plug wells yet? What plugs does it have in?

Mick