Leaking Crank-case Seal ??

[andrew]

I've been wondering if I have a leaking flywheel-side crank case seal, from a number of things that are/have happened lately:
1. I siezed a motor last year, running at WOT. Couldn't work out why.
2. Had a 155 main in, and was getting a runnaway condition. Went to a 158 and had no further problem, but now my plug gets a bit wet and I get spooge from the pipe.
3. bike is now getting hard to start. 15-20 kicks, then it will start easily, but if I let it sit between moto's it won't start again

I have noticed the reeds don't sit flat, tried turning them over but they've been turned too often. Will this create hard starting?

Should a '96 bike have worn seals so soon?

When I got the bike two years ago, it had a lot of oily stuff behind the cover, but after i cleaned it out it seemed to stay dry.

BTW, '96 200, ported, rad valve, 158/45, standard needle

Opinions, anyone??

 

[kdxquebec]

do you have oil in your cover again?If yes it is premix 2 stroke oil .I replaced left seal on mine this spring .After this it was a leak again .I sugest you to try this trik before change your seal $$$$(split case)This is comming from a member ........., Good luck!


you might want to check on a common problem there was on the 89-94 kdx's with oil in the ign. cover.You will have to take the flywheel and stater off and check the area around the seal ,there are 3 slots cast into the case, pg 7-6 in the shop manual far left picture.With a all or nail try to see if you can pick some aluminum from these slots ,if you can see steel under this then this maybe the problem.The steel material you see is part of the sleeve that is cast into the case and is what the crank bearings are pressed into.When the engine is started the two materials expand at different rates and you get a little bit of oil seeping between the case and sleeve.To repair this clean the slots as best you can with contact cleaner and fill the 3 slots with JB weld,you can lean the bike on its right side and this will make the JB weld stay in the slots,also check to see if there is any radial play in the bearings,just grab the end of the crankshaft and see if there is any up or down movement , if there is it maybe time for new bearings.Hope it is just a leaking case its a simple fix and can be done in a few hours, good luck.

 

[kevinkdx]

what he said, take off the cover and check for 2 stroke mixture. I had this problem and burned up 2 pistons and a cylinder(ouch) before i came on here to see what the problem was. I sent it to http://2fastracing.com and they did a good job and it was cheap.

 

[jdbrusch]

Have you tried to do a leak down test on the motor .This can tell you alot in regards to the condition of the seals and the rest of the motor?I would recommend replacing the reeds if they do not seal(lay flat) after flipping them over. The crank seals that kawi uses I believe in these bikes are just a general purpose seal almost the same that are on the wheel bearings and only good for temp. up to @ 250degrees F overheating may have hardend them,the bikes usually run @ 200-210 deg F .you can check with a local seal supplier for a higher temp seal ,maybe Viton or Silicone they are more $ but may stand up better to the temps down under. :)

 

[BucKat]

Hey jdbrusch,,
I'm replacing my seals while my engine is apart...Where might one get one of those heavy duty seals...
Thanks
Joe

 

[jdbrusch]

BucKat look in the Yellow pages under (Seals- Oil Grease,Etc) you may also be able to find them at a bearing shop, you can get the crank bearings from them.Stay with NTN or SKF these are high end brands and are still cheaper than the stock ones from Kawi I just got mine and they were under $30 can. for both,the part# is 6305 C3 make sure they are a C3 this is the clearance built into the bearing for running at the temp of the motor.They sometimes come with rubber seals or metal shields but you can just pop these out with a small pick.The seal size is 25x40x6mm and make sure to get double lipped ones.The bearings and seals are the same on both sides so make sure to get 2 of each.Unfortunatly I think the Viton and Silicone seals are fairly pricey and may not be worth the extra money.

 

[BucKat]

Thanks jdbrusch...
I'll give a look in the yeller pages.
later
Joe