2001 mxc 250 mystery oil leak

[taps]

I have a new to me mxc 250, and I have oil appearing on (what seems to me to be) a weird spot. It is just below the kickstarter and above/forward of the swingarm pivot attaching location. It certainly seems to be oil, but I'm not sure what I need to look at replacing.



You can see my finger pointing to the oil. You can see the kickstarter above my hand



This is the other view. The oil is on the case behind the brake line in this pic--just above the pivot.

Thoughts?

[bajadog]

You pictures did not show up, but it sounds like transmission oil since
you have a two stroke.

[taps]

Originally Posted by bajadog

You pictures did not show up, but it sounds like transmission oil since
you have a two stroke.

while yes, I do think it is trans oil, I was more concerned with the way in which it came out of the transmission. I find it leaking from where the cases a little odd, but that is all I can figure. Are there any other locations it could be leaking that are more likely?

[bajadog]

That was weird. The photos did not show up on my work PC, but do on my
home Mac.

Anyway, I'd start out with a clean slate.

1st Is the tranny oil low?

2nd If not, then is must be a "weeping" type leak. So clean up the
area with brake cleaner. Then ride it just enough to get it too hot to
touch. I usually get a small bottle of baby powder (the new stuff is corn starch). Squeeze that stuff in puffs around the area in your photos
as the engine cools down. You might have to repeat.
That should show you which gasket is compromised.

[taps]

Originally Posted by bajadog

That was weird. The photos did not show up on my work PC, but do on my
home Mac.

Anyway, I'd start out with a clean slate.

1st Is the tranny oil low?

2nd If not, then is must be a "weeping" type leak. So clean up the
area with brake cleaner. Then ride it just enough to get it too hot to
touch. I usually get a small bottle of baby powder (the new stuff is corn starch). Squeeze that stuff in puffs around the area in your photos
as the engine cools down. You might have to repeat.
That should show you which gasket is compromised.

I'm currently doing that. The brilliant previous owner (or previous previous owner) managed to strip out the check plug hole. They pushed it back in, and that (surprisingly) didn't leak, but I won't have a replacement bolt/plug until tomorrow evening. I was happy to see that the original plug ripped the threads from only a small portion of the threaded hole. I had to do some hunting to find a longer M10 1.0 bolt, but as I said, I should have that tomorrow. That done, I'll do as you say. Curiously, it looks as if the suspect gasket is reasonably new. Whatever the case, I topped off the trans oil, and used brake clean on the bottom/rear of the engine.

I had to put a kit in the rear m/c this evening, and now all my attention goes toward the leak.

[taps]

There is certainly oil just below the kick starter shaft bulge when I'm first noticing oil. That would make it two gaskets in. Does the top end have to be removed to split there? It is hard to tell from the drawings, but I am leaning towards no. If that is the case, I suppose the easiest thing to do is pull the engine and get to splitting. I hate to do that, but I guess if I want the leak fixed, that is in the cards.

One thing I do find curious is the amount of oil that comes out once it is running. After a fairly short time, there is oil on the swingarm. For a leak that does not appear until it is running, it is quite a leak when running. How common are case leaks like this--how common are cracks in casings?

BTW, I did check torque on all the cover bolts, and they were all tight.

Also, I got a flat doing the test ride around the backyard. Ripped the stem right off the tube. This is the way it goes.

[taps]

After checking the engine service manual and looking at the parts diagrams, I am beginning to think that I won't even need to remove the engine to get this done. Since I'm down waiting on a tube anyway, I may go ahead and have at it this week.

I should have bought bikes with the same tire sizes.

[taps]

So this happened...

And I found this...

And this bent thing...

I shot an email off to Chip @ Munn to see about the parts. Hopefully he'll have everything in stock, and I'll be back in business soon. At least there was a readily apparent cause for the oil leak. I would not be surprised if I tore the gasket taking it off, but considering that it is in the exact location of the leak, I'm betting we found our culprit.

Until later!

[taps]

So the bent linkage...

I have a new one on the way, but the manual is brief regarding adjustment: "Adjust linkage length if necessary"



How should it be adjusted? make it the longest it can be where it still fits on the pivot balls? I hate to have other tech questions in this thread, but I would not have found it were I not fixing the leak--I would not have suspected funky linkage with how the bike runs.

[bajadog]

Wow, glad you found that gasket.

I'd ask Chip about that power valve linkage adjustment, he
is a 2 stroke guru.