TS 250 Oil Leak

[veloce2003]

Hi, I seem to have an oil leak from the primary drive side cover of the engine of my TS250. I intend replacing the gasket this weekend. Is there anything I should be aware of when removing the primary drive cover? Can I remove it without taking off the kick starter? Thanks Michel

[Blurredman]

Hi,

The kick starter assembly comes with the primary drive cover. The main things you need to remember other than the main bolts (flat heads around the circumfrance of the cover) is the worm drive gear beneath the smaller cover that you may or may not have a tacho cable coming from.. This also acts as a nut on the end of the crankshaft and MUST BE REMOVED.

Otherwise if you don't you might end up doing something silly.

[parrbd]

That smaller cover is often the source of an oil leak. It might need a new O Ring.

[veloce2003]

Thanks fellas really appreciate your help. Before I take off the clutch cover I'll try changing the o ring of the clutch adjustment cover. Cheers Michel

[Blurredman]

I know it is quite difficult to track oil leaks, esspecially when you are using the bike....

But is it not worth wiping the engine clean, and then simply following the trail of oil to where it is coming from? It sounds simple= but can be quite difficult. If you can do this, and let it stand for a few days, it might be advantageous before taking the clutch cover off? indeed it could be the o ring, it is possible to also be the level screw, or the main drive gasket, but it could also of course be the o ring inside the gear shifter entrance, or as simple as the clutch adjustment 'tube' not being tight enough.

I know- i've been there.. I'm still trying to trace a leak.. I think mine is the drain bolt

[Puffs]

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[veloce2003]

Thanks again for all of the helpful suggestions. Something I didn't realise until speakng with Phil Speakman of the MZ shop that the cheesehead screws holding on the clutch cover have aluminium crush washers to prevent oil leaks. Interesting. What a lovely chap to speak to. Cheers Michel

[veloce2003]

Happy to report that I have now fixed the oil leak. New crush washers did the trick. When I drained the oil off there was over 1litre of oil rather than 750cc. I guess the previous owner must have vastly over filled it. Cheers Michel

[Blurredman]

I'm glad you got it fixed.. Yes there is certainly a copper crush washer on the most southern bolt that tolds the tacho assembly on, as well as a copper crusher on the southern most side case screws and filler screw.

[Kruh]

On the subject of oil leaks, my TS 250/1 is leaking from the ignition side crankshaft seal.

Previosly I had the green seal which let loose. I noticed leakage from it. So I replaced it with the expensive Viton double lip seal. After a few hundred kilometers it too started leaking.

The fuel/air mixture was and still is good and bike ran just fine with the previous leaky seal and is still running great with the current leaky seal. I didn't even notice any changes going from the leaky seal to a brand new one.
I wouldn't even know anything was wrong if I had not look under the cover.
Seems very odd to me, that there are no apparent issues eve though the seal seems to be leaking quite a bit.

I do not know why both 2 seals let loose. I do not see anything apparent thats wrong.
Could this be a normal occurrence on MZ bikes?

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[Kruh]

I rebuilt the engine not that long ago.
All of the bearing were brand new. The crankshaft I didn't touch since there was no play. As far as I know the engine was never taken apart before me. I heated the inner bearing race when installing the crankshaft. So I went with the assumtion that the crank is good.

I don't know about the speckles. Looks odd to me as well.
Maybe its just oil that was thrown around by the shaft as it was leaking?

But usually when the outside seal goes bad, there is usually a lean condition. But the bike runs completely fine. I've experienced on other bike that they would have a hard time even starting
That confuses me

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[Kruh]

A rough crank axle seems the most likey to me.

The bike vibrates a bit, but I would say its normal. It definetly isn't excessive. I've never experienced any other MZ before, so I have no point of comparisson.

I'm not 100% sure where exactly it's coming from. But I think its between the axle and seal and as the axle is spinning its flinging oil around, hence the speckles.


In any case the seal should be replaced. So I'll take it out and check the crank axle surface. Also I'll add sealent on the outside of the seal, just in case there might also be a leak there.
Might be a dumb question but just another idea, is there a chance there is some sort of isssue withe the discs that are between the bearing and seal. Maybe they cause excessive pressure or something. Anything to check there while its dissassembeld?

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