TS250/1 - 5 speed

[mick]

Cheers Puffs.
I never thought that it might be a factory mod so I am relieved to hear you have seen this before. The nuts and tab washers were in place and tight when I took the clutch apart yesterday, talk about belt and braces. The welds look smashing and obviously done by an expert and I feel much better about re-fitting it now the doubt has been taken away.
The thin oil plates for the main bearings are still lurking in the postal system due to the strike, but now I have a tracking number for them I should be able to put this engine together soon.

[Puffs]

Removed

[mick]

I agree about the maintenance as my clutch has some surface rusting where the plates have been sitting for years against the clutch body, and will be a bit awkward to clean, but otherwise should be ok.

[mick]

I now have the crankshaft and the gear cluster in the LH crankcase but have been stopped in my tracks by the small rubber oil separating disc that should also be fitted into the LH case. The disc is about 11.35mm diameter and the recess in the case is 9mm and I am buggered if I can fit the bloody thing as it just folds in on itself and I have dropped it down the narrow slot adjacent to it once already.
Can I ask if are there any differences between the 250 cc models of engines?

[Blurredman]

Are you talking about the black rubber disc that sits between the crankcases at the top behind the conrod? Yes they can compress and deform a bit but I've re-used them. However, if you have problems I would replace- you can get them on e-Bay.

There are differences to all 250 engines, depending on release and model of bike. It seems like they perfected it as much as they could though with tuning and port timing as much as they think they could though by the time 1989-1991 came around, although there is some variation of barrel height (and therefore port height). But lots of things were changed over the years some small things some big, dependsif you wanted to know something specifically? I have three MZ's @ 250cc base engine, but I have yet to actually try out the MZ TS250 5 speed which apparently is the best. But I would like to try that out for myself. I like the 4 speed Trophy, though it is hard to use sometimes, but I really enjoy my '87 ETZ250 (bored to 298cc), which I don't have a problem with what people call a peaky engine. A bit of tuning and richening of the low RPM range torques it up really nicely in my opinion, with barely any fuel consumption chart degredation. I'm not such a fan of my ETZ251, but it's still a fine bike, but not really 'enjoyable' in the same way as the others - in my opinion. Maybe it's the seating position, or the shortness of the bike. As, just as the engines are all different and have varying degrees of design, the bikes themselves also have different characteristics, which may add or remove to any experience if just comparing the engine alone. The 251 also has a really clunky gearbox (compared to my ETZ250) which I never did get to the bottom of. I think it's just had serious abuse in the past maybe.

Anyway: as for rust marks on your clutch plates and body. You can try and clear them away but in the end, it might just be plain easier to leave it and let the clutch itself rub all this away in the natural process of running the bike. Maybe?

[mick]

Thank you Burredman.
I have tried a dozen times to fit this rubber disc without any joy as it is quite tuff rubber and simply folds over on me, perhaps I'm just a fanny
I will try it next after dunking it in hot water and see what that does, and if its no joy I will do what you suggest and try ebay and hope for better luck as they may use a softer rubber.
I was hoping to have this engine finished before Christmas as the build cost is a present for a mate and I have already lost two weeks due to parts being trapped in the postal strike.

[Blurredman]

Ah yes, I've also encountered it not liking to stay in, but it's true that it should be thicker than the recess depth I think, in order to provide the seal that is required. Are you able to provide picture of what shape it is in when you install it into the recess?


And.. You have no excuse, you started this thread in September!

Ah- I only joke, I myself also have many things on. Indeed, I have to re-build an ETZ250 engine myself, which is next on my list of 'things to do to automobiles' coincidentally.

[Puffs]

Removed

[mick]

Thanks again for your replies.
I dropped the disc into hot water and got it to fit into the recess, but because the recess is not a full circle the disc bulges out into the space in the casting, a bit like rolling your tongue up. I found the ebay seller and they say the disc they sell are 9.5mm which is much more like it and should fit a treat. Ta

[mick]

Hi Folks.
Just another update on the snail pace rebuild of this 250 MZ. I received the alternative rubber sealing disc for it but it was bigger than 9.5mm but smaller that the other so I have used it to bolt the crank cases together. It has been on the back burner for the last month because re-assembling the clutch proved to be impossible for me at leased.
I thought I could use the clutch centre to assemble the plates, but the driven plates cannot be dropped over the combined primary gear because there is not enough clearance for them. I tried fitting all the plates into the toothed rim for the clutch but the clutch centre proved impossible to feed all the way down through the combined pack of plates.
I bought new toothed rim and clutch body and only then noticed the new toothed rim was drilled for six bolts to hold it to the clutch body and after seeing the factory video that their were supposed to be six spacing washers under the pressure plate and the price of these from Germany was about 16/19 euros each.
Can anyone say is these are special ground spacers to keep the pressure plat flat.
Ta

[Puffs]

Removed

[mick]

Hi Puffs.
I just mean that the normal toothed rim has tapped holes in it to bolt on the clutch body and the body has through holes in it to except the bolts. The welded version does not have these holes because the clutch body/toothed rim are welded together.
If you place the welded version face down on the bench and drop the plates into it you have to have all the plates inner tangs aligned in order to fit in onto the clutch centre.
On the question of the spacers I would say that the pressure plate has to be completely flat so that the clutch arm face hits the bearing square on with even contact .
On another subject can you give any idea as to a good make of front tyre for this bike.
Ta

[Puffs]

Removed

[mick]

Cheers Puffs that's great info on the tyres, just what I was after. On the clutch issue can I ask if you put any washers or spacers under mounting points of the pressure plate. Looking at the factory video it looks like the the spacers they use under the front pressure plate are just 6mm ID washer that sit onto the 8mm shoulder of the stud.
I had another go at fitting all the plates by using the clutch centre to fit the fibre plate then removing it and putting a steel plate in and then another fibre one followed by fitting the clutch centre again, if you keep doing this you can get all the plates in these welded up clutches.
Then you have to either make the factory assemble tool or bore out piece of round alloy bar at least 75mm OD with a bore of 65mm and 25mm thick and use this to site on while you fit the pressure plate and springs. I used my press to compress the plate just enough to spin the nuts on and finish with a socket.

[Blurredman]

Yes,

You need the washers between the pressure plate and the main clutch body. I can only think they're in place to perhaps stop the clutch being actuated 'too far', this would have the clutch basket contacting the primary gear potentially.


Anyway, I tend to press down the pressure plate with my hands, but ideally you want to use the pressure plate compressor tool but it's not necessary. You can put it in the vice or use G clamps too.


The difficulty is you need to first put down the gear that goes inside the clutch, then build it from there, allowing the alignment of the friction plates then and there instead of trying to combat trying this, which is pretty much impossible, afterwards, welded clutch or not.