Arcing plug caps?

[DEVO.RU]

Anyone know the cause of plug caps arcing off the head?been trying to get both my fzr's running but both are suffering from it. On both bikes its cylinders 3&4.i borrowed a set of coils for the 1000 but those are arcing also.at my wits end with both bikes now.always had yamahas but seriously getting sick to the back teeth with them.

[Stig]

It may be the actual coil body itself. Sometimes the plastics crack but very fine. Alt it may be a duff lead or plug cap

Try taking coil 1&2 off the good runner and swap it for 3&4 on the other bike. In theory it should make one bike run correctly

Could also try swapping just the leads or/and caps

[DEVO.RU]

Ive tried swapping the plug caps.had ngk ones on them,still arcing.replaced originals and wrapped them with tape.still arcing.borrowed a full set of coils,still arcing.the only spark il see soon is out of a Zippo and i torch the bastid.