KDXRIDER.NET

Hi
I bought last year a 2k kdx220 with only minor problem an oil leak at the output shaft (sprocket shaft). Laet last summer I taught maybe sand was in the collar or seal and did a little cleanup and fine grit sanding on the collar whitout success.
This summer I replaced the seal, collar and both o-ring, 2 days after i saw it was still leaking. I work as a mechanics but I tought maybe I missed my shot at inserting the seal cuz I used a flat end punch to drive it in, so here I go again replacing the whole package using a big socket to make sure I insert the seal as straight as possible. Once again this nasty leak is laughting at me. I tried different sprocket and circlips (thx to brother in law 2 kdx220) in case of a load pressure problem on the oring but still leaking. No crack seem visible on the casing and the output shaft have a little axial play (in and out) but no radial one (up/down) so no reason to affect the leak.
I dont even have to start it, drive it or installing the chain to see the leak slowly occuring, just put it on the stand and wait. The oil level is ok by the way.

So have someone seen that or can help me out? At this point im open to any suggestion!

How bad is the leak? Have you tried just ignoring it? Mine leaks / seeps there and I have found the best way to fix it is to stop looking at it.

rbates9 wrote:How bad is the leak? Have you tried just ignoring it? Mine leaks / seeps there and I have found the best way to fix it is to stop looking at it.

Not that bad actually, it make an 8" ring in sand after 2 week on stand and oil level stays in near-full range. Last ride I ran it about 150km and level was still between min and max. Ignoring it would be awesome unfortunatly I clean my bike good as new after each ride and this dirty spot drive me nutz plus the skid plate is a pain in the a$$ to clean when filled with the oily sand mix. And I like my bikes in good condition too!

You should try to put a " shim " behind your sproket to remove this in/out play... it put some pressure on the seal/orings and worked for me, over 2 years using this and no more leak..

JoKDX220r wrote:You should try to put a " shim " behind your sproket to remove this in/out play... it put some pressure on the seal/orings and worked for me, over 2 years using this and no more leak..

Thanks for the reply but as stated above I tried different sprocket and circlip to make sure I achieved enough pressure on the o-ring with parts from 2 other dry kdx220, I too suspected that because my circlip was kinda loose but nice and tight parts did nothing good.
Plus when bad orings sealing occur as far as I know(I know because I once busted one ) oil can be seen leaking from the splines in front of the sprocket, in my case oil leak along the crankcase no oil visible out of sprocket.
The in/out play, as mentioned, is in the shaft ;Only correlation between shaft, its bearings and crankcases can be involved in this play.

Is it leaking between the case and the seal or the seal and the collar? There has also bee some mention of people having the case leak from where the steel bearing pocket comes through the case behind the sprocket.

you can try a bigger size o-ring.

rbates9 wrote:Is it leaking between the case and the seal or the seal and the collar? There has also bee some mention of people having the case leak from where the steel bearing pocket comes through the case behind the sprocket.

Like if the bearing cracked the case ok the chain chewed it up? I just saw an old post about same unresolved problem you answered to talking about the 3 rectangular bearing inserts is that what you were talking about? As far as from exterior damage theres only a minor chain grind. I cant tell for sure if leak is between case and seal or seal and sleeve or somewhere near. This weekend ill put a sleeve instead of sprocket to have a better view of the exact place the leak is occuring after a cleanup and ill keep you updated next week, the bike is at cottage far up north in quebec,canada so no internet or cellphone signal. thanks for your support!

Ive had problems with mine leaking as well, annoyed the hell out of me. I ended up installing the seal with silicone around the outside to ensure that it doesn't leak from around it and not the seal itself. found out I have a tiny hairline crack on the casing where the seal goes in, fixed it with JB weld, had to sand it out to get better adhesion

I fixed my CS leak by putting a shim made of cereal box cardboard behind the sprocket. It was a bear putting on the circlip, but it definitely fixed my leak.

Back from the long weekend here are the good news,
I removed the sprocket and applied pressure on collar with a visegrip and finally had a nice view of the leak area. A little cleanup and 10min of wait later, the leak showed up coming between the seal and case at what seem like a tiny dent or maybe an hairline crack as KDXrider1989 experienced. I was expecting a bigger problem than that but once again the K.I.S.S law was right! A new seal with a little coat of Permatex Right Stuff® around it ''sealed the deal''

Thanks y'all for your suggestions

Glad you got it!