Hey guys,
Changed the spark plugs on my 94 Ninja 250 and noticed that the top portion of the threads on both plugs were oily...as if I'd poured a small amount of oil down into the spark plug tubes. I searched through the fiches to try and find the culprit and was wondering if anyone could confirm / deny what I think the cause is. Please see picture and let me know. If it gets worse, I'm afraid my plugs will be drowning in oil before long.

Thanks

 

i'd suspect the spark plug tube gaskets.

(as i'm sure you are, with the red circle and all..)

try a sequenced tightening of the valve cover..

inspect after a few hours of operation.

if the tubes still sho evidence of leakage, i'd go next to inspecting the seals with a disassembly of the top of the head..

just remove the cover and inspect the top gaskets.. the one you have circled is actually under the cam bearing cap, and you'll need the tightening sequence and torque value and all that if you were to attack these gaskets.

if you do have all the specs and a good torque wrench, and wanna go on and do all the seals, you won't need to remove the cams, but i'd loosen em all up in seq., then leave one cap on just barely snug, to keep the cams in place and from jumping timing.

just for your info.. the oil won't short the plugs out. the dielctric strenght of the oil is much higher than the voltage thespark plugs see.. still not good tho..[8D]

good luck, keep us posted, and welcome to KF!

 

Thanks for the info. Not sure if this stuff is in the service manual I have, but I'll give it a look. Hopefully tightening down the valve cover will do the trick. Could I get that lucky? :-) We'll see. Actually, I need to replace the valve cover gaskets anyway....there's seepage there as well. Fun fun.