Motorcycle Repair: 1990 Kawasaki Vulcan (EN500A) engine power loss, kawasaki vulcan, air filter oil

Question
Hi Mark - My bike was running good until my son cleaned and over oiled the air element and didn't take off the excess oil. The following day I took it for a long ride and as soon as I hit 60 M.P.H. it slowed down to 50 M.P.H. even with the throttle wide open.I took off the oily air filter on the way back home and I could do up to 85 M.P.H. but she was missing a bit. Just before the problem, I once took her up to 115 M.P.H. without any loss of power. I cleaned the air filter, replaced the badly fouled up plugs, cleaned the air valves, cleaned carbs (they were not clogged up), checked the vaccum valve and took her for a spin - same problem. I checked the plugs again and they were fouled up with a black carbon deposit.  The bike starts good, idles ok and is a bit sluggish on power but will not do more that 60 M.P.H. Even on high rev in neutral she will miss. What would you suspect?(IC Ignitor)? I guess it's a coincidence that the problem started after the air filter error.
Please Help - Andy

Answer
Hi Andre,

Sounds as if you investigated the engine components thoroughly. I would need to do the same in order to troubleshoot the symptoms.

Maybe a sensor or other part of the fuel evaporative system has become contaminated by the air filter oil. I doubt the CDI is defective.

Visit Kawasaki's or Bike Bandit's websites to see microfiche parts views:

www.bikebandit.com
www.buykawasaki.com


Here's a couple of resourceful Vulcan websites:

http://www.gadgetjq.com/gadgetsfixitpage.htm

http://www.vroc.org/index.php?sid=d2bf49a7cd654e9cd842b0d0b101fcee

Respectfully,
Mark Shively