This makes no sense to me

[tuckerchef]

I have a 05 summit x 1000 sdi. it's been fouling plugs like mad until I upped the idle to 1800 rpm. now I'm it's only running on one cylinder. If I remove the plug wire from the non firing plug I get an arc from the wire to the plug and the cylinder fires up for as long as I hold the wire near the plug. Put the wire back on the plug and I lose that cylinder again. Any suggestions?

 

[Bnorth]

Check compression, check the boot. Might be making poor contact when it's on the plug.

 

[Nedder]

I would try changeing the plugs, if you already have'nt done this ?

 

[Trashy]

Your plug cap and coil both have threaded ends. Make sure that they are both screwed on tight to the wire. I would also check the compression too.