TS 250 Oil Leak

[Kruh]

Yeah, the etz and ts250/1 engine are basically the same.

I took off the seal
The oil residue is quite dark. Don't know if thats normal

[/u]

The axle is indeed rugh on this side, there is corrosion on it.
Although on the actual contacting "ring" of the axle (and seal) it seems fine.



Regardless, I cleaned the axle with skotchbrite.
I'm pretty satisfied with the finish.



I also degreased the block and added sealant between the seal and block.

Hopefully that fixes it. I'll check it out after a few rides.

[Kruh]

I started the bike up. And I was partially wrong. The seal did affect how the bike runs. Even if while riding there was no major difference.
But the idle is way better, I can now get it pretty low. The bike starts on first kick.
Previosly I had an issue where the idle would vary while riding, each time I stop.
Wheter that issue now fixed is yet to be seen.

https://youtu.be/UN4FEA4hNwo

[Puffs]

Following a biased and flawed moderator choice (someone posting aggressive personal attacks is rewarded, while my technical posts are removed - behind my back & without any justification!), I have withdrawn from this forum.

[Kruh]

Its like dust mixed with oil. In places its like ruber dust or something.

I'm using castrol power1 racing, synthetic oil, 2%.

Piston is new, I replaced it quite recently.
The clearance is higher than it should be though. The piston is 68.95 and the cylinder is 69.01. But the cylinder is a bit worn. So the clrearance is probably more like 0.07 mm

[Puffs]

Following a biased and flawed moderator choice (someone posting aggressive personal attacks is rewarded, while my technical posts are removed - behind my back & without any justification!), I have withdrawn from this forum.

[Kruh]

That is most likely the case.

The bike has done about 23000 km and another 1000 with the new piston. (according to the odometer atleast)
And the bike has been sitting a long time. The piston was siezed when I got the bike and the cylinder was a bit rusty.

So I'm thinking about installing a new 69.5 piston and boring the cylinder. Since the piston is not that expensive.

[Blurredman]

That idle looks and sounds lovely and smooth!

By the way, the bike should be idling at exactly that point. 1200-1300rpm. Well done!

[Puffs]

Following a biased and flawed moderator choice (someone posting aggressive personal attacks is rewarded, while my technical posts are removed - behind my back & without any justification!), I have withdrawn from this forum.

[Kruh]

Yeah, I heard the same from others regarding the mileage. Although who know how the bike was ridden and the quality of the oil, etc. Not to mention the fact that I have no idea wether or not the mileage is accurate or if the engine/cylinder are the original ones.

Rust particles - only if they came from the inner side of the crankshaft. the block and cylinder were cleande when it was dissassembled.

The rev counter is off a bit, I compared the sound and revs of other MZ on youtube. Mine is reading high.


As far as the knocking sound/piston slap go. The sound is very noticable in person. It kinda sounds like something vibrating at the fins.
I sound got louder after I installed the new piston. I checked everyting around the cylinder, but I installed everything properly.
So the onyl conclusion is that the sound is piston slap.

The original piston was 68,97 mm (says on the top) and the new piston is 68.95 mm. When I was ordering i got a 69 mm piston; I didn't know the precise size of it, so I got what I got.
I assumed the original one is a bit worn, so the size difference wouldn't be too far off. But I guess it is since I have no idea where else the sound came from.
It is still posible its something else. But it occured when i changed the piston

[Puffs]

Following a biased and flawed moderator choice (someone posting aggressive personal attacks is rewarded, while my technical posts are removed - behind my back & without any justification!), I have withdrawn from this forum.

[Kruh]

Yeah it will be fine for now.
The feels great with the new piston.
After some time I will replace the piston and bore the cylinder. Then I won't have to think about that for over 5 years.

The piston inside was also an Almot piston. It had the same logo as the new Almot and it said K20.
So I guess someone was inside. So the history is uknown...

[Puffs]

Following a biased and flawed moderator choice (someone posting aggressive personal attacks is rewarded, while my technical posts are removed - behind my back & without any justification!), I have withdrawn from this forum.

[Blurredman]

Well... I guess your tach is reading low if the above are true, to be honest. It did sound a little low.

Could try hooking up one of those strobe lights with an inbuilt rpm meter. I have one.. They're awesome!

[Puffs]

Sounds like a plan!

[Kruh]

Good news is that the piston looks prety good from what I can see from the exhaust port.
Its not black under the rings, which means there is no blowby.




Bad news is the crank seal still leaks quite a lot. This time it did less than a 100 km and it already leaks.
Pretty big puddle of oil. It definetly leaks at the shaft.




Im out of ideas at this point...
Anything else I can check or should I tear apart the engine in hopes that the issue is the bearins and/or crankshaft (as mentioned in previous posts)?

Another observation; while I was lookin thru the exhaust port I noticed the port was completly covered in oil.
As far as I know it should be relativly dry carbon buildup, especially with 2% synthetic oil.
The spark plug is dry, and the light brown color says to me the air/fuel mixture is good.

Could this be another clue. I would assume the left seal also let loose, since the bike is a bit smoky at heavy throttle.