Firing on one cylinder-HELP??

[xlr8n_xb]

Went for 150 mile ride last Saturday with 15 other guys here in upstate NY. We pushed it pretty good but stopped every 30 mins or so. Sunday morning when I went to go for a ride, after 4 or 5 miles my '05 XB12R started popping and backfiring horrible. Then it just started going between cylinders it seemed like. Like it was half power. When I got it back home it stalled in the driveway. I took the plugs out and they were super black so I switched them out figuring they had been fouled. Now when I start it up it starts only on 1 cylinder but intermittently will fire the 2nd. Any idea what this could be? I ordered a coil pack and wires figuring something was wrong with the wires but have yet to receive them. Any other ideas of what it might be before I get into it to far? Also when I had the base plate off the air box there was nasty oil on the front cylinder head that appears to have blown from the breather cap. Can you replace that cap. the front one is way looser than the rear cylinder breather cap. Thanks for any help or advice. All is super appreciated.

[Miami78]

Possibly a plug wire not fully seated? Or maybe fouling plugs again?

I would check the wires, make sure they are seated fully at both ends. If those are fine maybe try iridium plugs. Also a tps reset wouldn't be a bad idea if you are able. If those don't fix it new plug wires would be next, as yours could have been damaged when you swapped plugs.

For the breather cap, are all the connections tightened down with zip ties to prevent leakage? Might need some screw down hose clamps if zip ties are not cutting it.

[xlr8n_xb]

Thanks miami. I am going to be replacing the coil and wires together. I am currently doing the screw down clamps at all connections. I'll let ya know what happens.

[Andrew88M]

also check your breather seals that go into the rockerbox covers. had a problem with these leaking real bad had oil dripping down the side of my bike by the time I caught the problem and I only had like 500 miles on my bike but one of the seals went bad super fast.

[xlr8n_xb]

Im thinking the front one is bad. Its got a loose seal as it is right now. Was it easy to fix?