Okay so I was changing out my spark plugs because I figured I'd do a major tune up on the bike after getting it from a private owner and saw that the threads on the spark plugs had oil on them... Is that bad? Does it mean my motor has damage?

 

What I would do is change the plugs, drive it for a few days/couple weeks, watch your oil level and then check them again. It could be bad rings BUT it could also just be the owner put some oil on the plug threads to screw them in easier.

 

First if you didnt use the correct NKG plugs do not run the bike until you get the correct plugs you will damage your engine.


If you just have oil on the threads look and see if the valve cover gaskets that go around the top of theplug openings are leaking. One of mine leaks probably has since the last valve adjustment I get a tiny drop of oil out the weephole on the side of the engine case every once in a while. I could definately see it on the spark plug threads. Im not worrying about it unless it gets worse or the next valve adjustment.

Also you need to do a valve adjustment if you havent already or have a recipt from the PO doing it. Very important it gets done regularly.

 

Can you post up a pic? Oil on the threads past the indexing washerwould not really concern me.

 

Sorry I didn't get a picture of it.. I believe I did get the right replacement NGK spark plugs. The one suggested on the ninja250 forum. I screwed it in finger tight and then an extra 225deg rotation with a socket wrench. I hope that's enough torque. I have yet to turn the bike on. The oil was on the threading at the bottom of the spark plug, when I peered into the hole after the plug was out.. I noticed a little oil on the black park of the cylinder. I think its the gasket where the valve cover meets. Not sure.

edit: BTW, I was trying to adjust my valve clearance the same time i was changing the spark plugs and well, I couldn't get the valve cover off if my life depended on it! I unbolted and shifted the radiator/fan but it seemed the frame wasn't giving enough slack for the valve cover to wiggle out. How do you guys remove the valve cover, I was able to peak in and working on the valves looked like a PITA! Should I just let a mechanic do a major tune up for my bike? I mean I've worked on cars and adjusted car valves so I'm sure its similar but the clearances and space to work with on a bike is almost non existent!

 

hmm, I too hand tighten the plugs, the maybe a 1/4 turn more for snugging.
I am not alarmed when seeing oil or residue on the threads of the plugs,
"back part of the cylinder"? yes keep an eye out for leaks.

 

i have the same problem except for my 2 left spark plugs are getting pretty wet with a dark watery liquid, and i get absolutly no spark from any plug, how can i test the spark plugs for spark? i am pretty new to bikes

 

So you are saying that while you are holding the electrode portion of the plug, you are not picking yourself off of the ground? Then I would say coil or wire issue. lol Kidding about holding the plug, not a good idea on checking the spark. Normally, I just do like most people and hold the plug close to a ground and look to see if the spark is strong or not.

 

it could have ben that the old owner put a little oil in the cylenders to keep the rings from sticking and the cylenders from rusting that is what i do when i put the bike up for the winter