oily spark plug

I recently picked up a 1999 kz100 police bike.. it was running pretty rough so I started with the spark plugs... The #3 plug was just covered with oil and as soon as I replaced it.. bike runs strong again but is blowing smoke like grandpa's nash rambler out of the right pipe. The engine only has 18000 miles on it.. are there any typical problenms with these engines that could be the culprit? My guess is a rotten oil seal on one of the valves but thought y'all might have some input

No telling how long it may have been run on just three cylinders.
Might be blowing out built up crud and clear up after a few more miles.
Meanwhile, if not already done, would perform a compression test.

Good Fortune!

Earth to Patton --- Just noticed this was poppadori's first post!

Hello, Jeff, and WELCOME to KZr!

We're glad you're here!

Good Fortune!

Thank you...glad to have found this forum...
I think you might be right about just burning out the oil.. the previous owner had this bike for over 5 years and only put 3000 miles on it, I have a feeling this set for a long time

You might have stuck rings, a product made by Yamaha called "Ring Free" should loosen up any stuck rings.

Another less expensive method would be to spray either PB Blaster or Kroil in the cylinders and let sit for a few days with the sparkplugs installed to keep dirt out.

Pull the plugs and using the special 13mm "nut" on the end of the right side of the crankshaft, turn it over a few times, install the plugs and fire it up(it's gonna smoke for a while).

a leek down test would be in order.

When removing the right side crankshaft cover(the old ignition points cover) you will see a 13 mm bolt holding the ignition advancer to the crank shaft,around it on the outer edge is a 17 mm false "Nut", this is what should be used to turn the crank over with when the sparkplugs are removed.

If the 13 mm bolt shears off inside the crankshaft, it can require the use of a machine shop to remove the broken piece. One of the forum members had this happen to them and it was not easy to remove.