Bad Oil Leak

This past weekend, I took my 08 450 XC-F out to my local track, and after riding for about an hour, I go back to my truck to refuel and rehydrate and notice a very noticeable amount of oil on the right side of my engine case. At first glance, there was so much oil I thought it was just mud and water from the track, but it was indeed all oil. The oil seems to be coming from the spark plug weep hole. I didnt have my manual with me, but I stopped by my local KTM dealership on the way home and I told him I just replaced the rubber gasket around the spark plug shaft, #9 in the diagram. The guy I talked to said that if I didnt seat that gasket perfectly, that could be why I am leaking oil, but once I cleaned my bike and could see into the sight glass, there was very little to no oil left. In other words, I would say I lost about 90-95% of my oil. Could that gasket really be the problem? I was thinking more like a worn head gasket or seal somewhere. I really dont think I would lose that much oil from that gasket being out of place.


I would put oil in it and run it and look for the oil leak again if it were me and then try to determine the source.

Wish I could help more.......sorry.


I'll give that a shot, but do you think that spark plug gasket being out of place would allow that much oil to leak out? I'm not saying thats the problem, but when I replaced it, I had it seated in the right place. Unless it moved when I put the head gasket back on, I cant see how that much oil would leak from that barely being out of place.

yes, it could leak that much in a day of riding

yes, it could leak that much in a day of riding

I was only riding for about an hour. I checked the oil before I headed to the track and it was full. After that hour most of the oil was gone.

Are you sure that much oil leaked out? If the oil is at the very bottom of the sight glass, then you didn't lose 95% of the oil. If you haven't done it already, drain the oil and measure how much came out.

I could only see a very small amount of oil when I leaned the bike on the side of the sight glass. I might have been wrong with my estimate, but regardless I lost a good amount of oil.

I did get into the bike and it apparently was the gasket around the spark plug opening. Somehow the gasket slipped when I put it on and when I took the head cover off the gasket had a fold crease in it. So it fell off and was folded when I put it on. That explains alot. I appreciate all the input.

After I got everything put back together, I noticed oil leaking out of what I think is the water pump weep hole. In the photo its behind the bottom screw on the water pump. From what I've read on the forums, it sounds like all I have to do is flip the water pump seal around since KTM apparently puts them in backwards. Should this solve my problem? The previous owner said he replaced water pump and seal not long after he got it. He said he put about 15-20Hrs on it after replacing. I have not seen anything leak from here until now. I've put about 8-10hrs on it.


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