Oil leaking from the crankcase cover

[Mr.Blue]

Hello everybody! I recently purchased my first bike, a used 2006 GZ250 from a dealer. However, I have begun to notice oil leaking on/in the locations in the photos. The oil does not leak when I park the bike and if it does it is minute but when I am riding and retrace my steps I notice that there is a large trail of oil following me wherever I go. I believe it may be the seals and am wondering for input from someone with more knowledge than I. In the location of the second photo the seal does seem to be coming off and there is a bolt missing as well so I believe that would cause the seal to loosen. However, when riding, I am losing leaving a significant trail of oil (in my 30 minute ride this morning I lost about a quarter of the oil in my engine). Does having a loose seal around the crankshaft have the possibility to produce such a spill or may there be a bigger problem? And, if it is just the seal, how difficult would changing them be for a new rider?

Thank you, Mr.Blue

[Vegas Street Rider]

Looks like you have a failed magneto cover gasket. With the missing bolt as well, that could be part of the issue. If it were me, I would order a new gasket and replace the missing bolt. If you go up to the top of the site page, go to search and type in manual and hit go. Half way down the page you will see the various manuals. Go to parts manual and look up the part numbers on about the 5th page. You should be able to find both online.

[Mr.Blue]

Ok thank you! How difficult would this be to do?

[Vegas Street Rider]

Hard to say as it depends on how handy you are and mechanically inclined. I have never had to replace the one on my GZ so it is just conjecture on my part. Hopefully, you will get some more input from other forum members.

This comes from someone that took apart his Lionel electric train engine and put it all back together at age 5.

[Gunk]

Sorry I'm a bit late to the party BUT

I just replaced mine after doing some monthly serive on my 01. Bought a gasket kit off eBay because of a small leak (ironic thing is the valve cover doesn't have a gasket Soni ordered it for no reason really) and just replaced any and all gaskets I could get to because the bikes never really had an owner who gave a fudge about it's lifespan until me.

Long story short, all you have to do is remove the 3 bolts holding the sprocket cover, and then remove the bolts from the cover, and with minimal pulling (the stator/alternator is magnetic, so it will resist a bit, but there should be no problems pulling it off. The only loose piece i found in there was the gear for the starter, which is easily placed back in there if it falls out place.

Scrape off any and all old gasket material, and replace, and then reverse the process. I would highly suggest replacing the bolts that are missing. Either bring them to a hardware store and find the right thread/length and either order a new stainless steel one, or pick one up there at the store.

All you need is (I think) a 10 & 11 mm socket and maybe a flathead to CAREFULLY pry the cover from the motor. Sometimes those gaskets stick and don't want to let go.

I also did this with the motor drained of oil, so I'm not 100% sure if you can do all this with our in the motor. I highly doubt it due to there was a small bit pill at the bottom of the case when I removed it.