no spark on cylinder #3

The other day I noticed a lack of power in the ol XJ. Pulled the plugs, and cylinder 3 isn't firing at all. I just replaced the ignition coil for 1 & 4 (with a used oem one). Could my issue be related to the other coil? I figured if the coil was dead I wouldn't get a spark on 2 or 3....

 

These are wasted spark engines. The only ways you're going to have only one cylinder without spark are if the plug's gap is bridged, or if the high voltage side for that cylinder is shorting to chassis somewhere along the way.

Check the plug.

Run the bike in the dark and look up under the tank for arcing from the #3 plug wire or the 2/3 coil.

Maybe a bad cap could cause problems, but I'm not that convinced of that.

 

Well It turns out I am getting spark, but the exhaust isn't even getting close to warm. I pulled the plug caps off and trimmed a little wire to expose some clean wire for the boot. This seemed to work perfect at first. Now I have a big problem though, just after I got done revving the bike up a little I noticed to oil leaks On either side of the bike. Bike has never leaked a drop of oil. I don't have much light in my garage and it's getting dark out now, so I'm unable to accurately pinpoint the leaks until tomorrow, but what do you guys think I'm gonna be getting myself into? I would imagine the oil leak and lack of power in cylinder 3 are related... Thanks, Kyle

 

I think you're in for some carb work.

You should probably check to see whether your oil sight glass is full when the bike's level. You may well have a bunch of gas in your crankcase, which will thin things out and get past seals and gaskets much more easily... sometimes it also runs into the airbox and down the drain hoses, so it may look like an oil leak.

#1 check for gas in the oil
#2 check compression
#3 check (and correct) valve clearances, if it hasn't been done recently
#4 probably going to be doing an overhaul on those carbs...