oil coming out from around new clutch release shaft seal

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chadr
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oil coming out from around new clutch release shaft seal

Post by chadr »

So I'm just getting some things in working order on this beat up kdx 200 I purchased last month ($280 gets you what you pay for I suppose). I replaced the clutch release shaft seal and oil was steadily flowing from there after a 10 minute ride. While it was still flowing I removed the oil fill plug and it stopped. I'll have to check the breather tube to see if it is plugged. Is the pressure coming from leaking main seals without a doubt? Other possibilities?
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Julien D
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Post by Julien D »

would have to be a leak between the cases or the RH main seal. No other way. There should not be that kind of pressure in the tranny. Check that the breather tube is clear and unclogged?
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Post by kdxmaniac »

sounds like your breather tube is cloged. take a cup of water{after making sure the tube is not cloged} and put the tube down in it while the bike is running, rev the bike up a couple times..........is the tube sucking water from the cup, or blowing bubbles..........or nothing?
my bikes
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96 ktm 300
96 XR400R
07 hayabusa
77 kz 1000
85 goldwing 1200
02 BIG DOG PITBULL

gone but not forgotten
96 kdx 200
98 ktm 380 "because it dang near killed me!"
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94 dr 350s
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kdxmaniac
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Post by kdxmaniac »

>|<>QBB<
juliend wrote:would have to be a leak between the cases or the RH main seal. No other way. There should not be that kind of pressure in the tranny. Check that the breather tube is clear and unclogged?
RH sitting on the bike? if the case was leaking, it would be sucking the fluid from the trans........and if the RH seal was bad, it would be sucking fluid...........the pressure could be from a cloged breather tube, or the kips seals could be bad?
my bikes
-------------
96 ktm 300
96 XR400R
07 hayabusa
77 kz 1000
85 goldwing 1200
02 BIG DOG PITBULL

gone but not forgotten
96 kdx 200
98 ktm 380 "because it dang near killed me!"
97 ktm 360
96 ktm 250
93 wr 250
94 dr 350s
93 kx 250
07 gsxr 1000
99 bandit 1200
chadr
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Post by chadr »

When I get a few minutes this evening I think I'll pull the breather connection out to check it. Probably better I don't start up the bike and rev it too loudly. Hopefully it doesn't crack too easy. Plastic 20 years old though... I bet it will break.
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Post by Julien D »

re:RH sitting on the bike? if the case was leaking, it would be sucking the fluid from the trans........and if the RH seal was bad, it would be sucking fluid...........the pressure could be from a cloged breather tube, or the kips seals could be bad?



Do what?

There is both positive and negative pressure in a 2 stroke crankcase dependent upon direction of stroke. It's basically an air pump, right? As the piston is rising, the volume of the crank case is expanding and pulling charge in through the reeds. When the piston begins descending, the area in the crank case is rapidly reduced, and the intake charge is then forced into the combustion chamber from the lower end by the positive pressure building in the crankcase.

Does this make sense? If a RH main seal is shot, yes, it will suck in transmission oil when the crankcase is under negative pressure. On the flip side, on the positive pressure side of the stroke it will be pushing intake charge intended for the cylinder into the tranny as well through the same leaky seal. The result is positive pressure inside the transmission, which should not naturally occur.

Oh yeah, same deal with a leak between the cases. Oil is sucked in from the tranny and then compressed intake charge is blown back through.

How do the kips seals relate? I see no path between the kips to the transmission.

So, are you losing tranny fluid?
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Post by kdxmaniac »

whatever is sucked it from the trans does not get blown back into the trans.........it gets blown out the exaust. thats why you get all that spooge when a crank seal is bad. yes you have crankcase pressure, just like all gas engines, but it not enough pressure to cause problems{unless you have no breather}

i know what im talking about from years of working on bikes. my wr had a crack between the cases from a bad lower rod bearing.....

as for the kips, it may not be like all other bikes.......i dont know on the kips, havent tore into the kdx yet, but just about all bikes with powervalves has to be conected to the trans.
my bikes
-------------
96 ktm 300
96 XR400R
07 hayabusa
77 kz 1000
85 goldwing 1200
02 BIG DOG PITBULL

gone but not forgotten
96 kdx 200
98 ktm 380 "because it dang near killed me!"
97 ktm 360
96 ktm 250
93 wr 250
94 dr 350s
93 kx 250
07 gsxr 1000
99 bandit 1200
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Post by Julien D »

Sure, whatever :)

I'm not sure how it could be much more simple. Here is what happens when the tranny side crank seal is leaking. And yes, that is the right side of the bike while you are "sitting on it".

while the intake charge is getting pulled into the crankcase, so is transmission oil through the seal.

While the intake charge is being expelled from the crankcase, so is that charge being pushed through the leaky seal into the tranny.

The pressure on the seals will be equal from both directions, just at different times.

Aside from this, crank case pressure has nothing to do with pressure in the transmission which is the OPS symptom. Transmission is sealed off from crankcase, correct? So if there is pressure there, where do you think it came from??

I'm sorry, I just can't make it any more plain than that. I can't much care what you think you know, or how long you been doin this, that's the way a 2 stroke works. What you think you have learned does not alter the physics of the thing. Alternating pressure.... It's a friggen air pump. A seal never fails in such a way that it only leaks in one direction. If it leaks oil in one way, it's going to leak compressed fuel/air the other way as well.
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Post by chadr »

re: So, are you losing tranny fluid?

Yes, but it may be only external leaks at this point. Now that I have new gaskets in the clutch cover and right side cover I see there is a problem relieving the pressure. I really haven't been able to get enough time on the bike to know since I'm still in the process of stopping the oil leak(s). So far I've ridden it for a couple of hours and I've changed the oil a few times. I don't smell anything stinking like burning 10w40 while I ride, but there is a good amount of 2 cycle smoke.

I'll post an update on what I find with the crankcase vent.

Thanks for the info guys.
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Post by kdxmaniac »

chadr.........try what i told you, and let me know what its doing.
my bikes
-------------
96 ktm 300
96 XR400R
07 hayabusa
77 kz 1000
85 goldwing 1200
02 BIG DOG PITBULL

gone but not forgotten
96 kdx 200
98 ktm 380 "because it dang near killed me!"
97 ktm 360
96 ktm 250
93 wr 250
94 dr 350s
93 kx 250
07 gsxr 1000
99 bandit 1200
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Post by kdxmaniac »

juliend............so what your saying is ,if the crank seal is leaking{RH}, then premix will be getting sucked into the crankcase????........and that you couldnt loose trans fluid because it gets sucked into the crankcase, and then gets blown back into the gearbox???? in other words, back and forth so no lose can happen.
my bikes
-------------
96 ktm 300
96 XR400R
07 hayabusa
77 kz 1000
85 goldwing 1200
02 BIG DOG PITBULL

gone but not forgotten
96 kdx 200
98 ktm 380 "because it dang near killed me!"
97 ktm 360
96 ktm 250
93 wr 250
94 dr 350s
93 kx 250
07 gsxr 1000
99 bandit 1200
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Post by Julien D »

No, that is nothing even close to what I am saying.
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Post by kdxmaniac »

>|<>QBB<
juliend wrote:Sure, whatever :)

I'm not sure how it could be much more simple. Here is what happens when the tranny side crank seal is leaking. And yes, that is the right side of the bike while you are "sitting on it".

while the intake charge is getting pulled into the crankcase, so is transmission oil through the seal.

While the intake charge is being expelled from the crankcase, so is that charge being pushed through the leaky seal into the tranny.

The pressure on the seals will be equal from both directions, just at different times.
.

thats what you said. if pressure gets pushed back into the gearbox, and trans fluid gets into the crankcase, then premix is in the crankcase, so premix would have to be pushed into the gearbox along with that "pressure" and gearbox oil acording to what your saying........right?
my bikes
-------------
96 ktm 300
96 XR400R
07 hayabusa
77 kz 1000
85 goldwing 1200
02 BIG DOG PITBULL

gone but not forgotten
96 kdx 200
98 ktm 380 "because it dang near killed me!"
97 ktm 360
96 ktm 250
93 wr 250
94 dr 350s
93 kx 250
07 gsxr 1000
99 bandit 1200
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Post by chadr »

removed the breather and found no block in the hose or fitting. While it was out I ran some air from my compressor through there just to be safe. I took a peek into where the fitting goes and could see nothing in the way.

The oil level is now 1/2 way up on the sight glass when bike is level.

If pressure could not have built up, must have been coincidence or imagination that removing the oil fill plug stopped the leak.

Finally, the lever and cover were really worn out. Lots of slop where the lever pivots in the housing. The lever has an area worn away by the spring but I figured this was too high to affect the seal. It would be sort of easy to build up the lever with a bit of welding and finish it round again. I might give that a try instead of getting a new lever ($25) and housing ($65).

I'm sure my main seals are leaking too - I just need to stop the oil leak for long enough to determine that :)
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Post by chadr »

just ran across this thread after a search. Sounds like I just need to get these parts on order and move on to the next issue.

http://kdxrider.net/forums/viewtopic.ph ... shaft+worn
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Post by Julien D »

Sounds like that would be a relief, as compared to your original thought.

http://www.vf750fd.com/blurbs/stroke.html

There's a pretty good explanation of 2 stroke combustion. You can see as the piston descends, pressure is increased in the lower crank case and the charge is forced through the relatively small transfer ports. That is how you would get pressure coming through the RH seal. This is also why a leaking LH seal will have evidence of premix behind the stator cover.


Hopefully this is not your issue, it's Just to clarify. It IS possible to have pressure in the transmission, but the only way for it to get there is through those crank seals. I suppose if the seal is bad at the actuator, the clutch is right behind there slinging oil, so leaking from there without any pressure certainly seems possible.
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Post by Julien D »

>|<>QBB<
kdxmaniac wrote:>|<>QBB<
juliend wrote:Sure, whatever :)

I'm not sure how it could be much more simple. Here is what happens when the tranny side crank seal is leaking. And yes, that is the right side of the bike while you are "sitting on it".

while the intake charge is getting pulled into the crankcase, so is transmission oil through the seal.

While the intake charge is being expelled from the crankcase, so is that charge being pushed through the leaky seal into the tranny.

The pressure on the seals will be equal from both directions, just at different times.
.

thats what you said. if pressure gets pushed back into the gearbox, and trans fluid gets into the crankcase, then premix is in the crankcase, so premix would have to be pushed into the gearbox along with that "pressure" and gearbox oil acording to what your saying........right?

Yes, premix would get pushed back through into the transmission. This is why an old 2 stroke with really bad main seals will have transmission oil which smells of premix, premix residue behind the LH stator cover, and it will ALSO be burning transmission oil. The transmission oil doesn't get sucked in and blown right back out though, as you said. It all gets mixed around in there with everything else, burns, and causes excessive spooge/smoke like you mentioned above.

Sorry, having a hard time understanding why you can't understand this. It's all pretty straightforward if you look at the function of a 2 stroke engine.

juliend............so what your saying is ,if the crank seal is leaking{RH}, then premix will be getting sucked into the crankcase????........and that you couldnt loose trans fluid because it gets sucked into the crankcase, and then gets blown back into the gearbox???? in other words, back and forth so no lose can happen.


THAT ^

Is not what I said.
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Post by frankenschwinn »

:pop:
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Post by kdxmaniac »

what time does the moon come out at night? the moon makes the tides come in, so maybe the moon has to do with seals leaking. see, when the moon is not out, your fluid level goes down.....thats why your bike dont leak at night. this is tru.....i read on the internet.
my bikes
-------------
96 ktm 300
96 XR400R
07 hayabusa
77 kz 1000
85 goldwing 1200
02 BIG DOG PITBULL

gone but not forgotten
96 kdx 200
98 ktm 380 "because it dang near killed me!"
97 ktm 360
96 ktm 250
93 wr 250
94 dr 350s
93 kx 250
07 gsxr 1000
99 bandit 1200
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Post by scheckaet »

>|<>QBB<
kdxmaniac wrote:what time does the moon come out at night? the moon makes the tides come in, so maybe the moon has to do with seals leaking. see, when the moon is not out, your fluid level goes down.....thats why your bike dont leak at night. this is tru.....i read on the internet.
:lol:
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