Clutch cable 250 ETZ

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Clutch cable 250 ETZ

Postby JawasandMZs » Mon Nov 23, 2020 2:18 pm

Hi, there's not much adjustment left at the handlebar end of the cable, the thread is nearly all out. Is there any way of adjusting the length at other end? And how do you change the cable please?
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Re: Clutch cable 250 ETZ

Postby Kruh » Mon Nov 23, 2020 2:26 pm

Yes, you can make an adjusment on the engine via turning the plate under the tachometer drive cover. Which will pull the cable in and out.

I'd suggest taking a look in the manual or the youtube videos for more details. There its shown better than I could ever explain here.

To change the cable, loosen the cable on the lever, take the rubber dust cover off (on the engine side of the cable), then you remove the plastic holder thats under that cover and lastly loosen that tube in which the cable goes.
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Re: Clutch cable 250 ETZ

Postby JawasandMZs » Mon Nov 23, 2020 2:53 pm

Kruh .. thanks!
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Re: Clutch cable 250 ETZ

Postby AlanJ » Tue Nov 24, 2020 4:55 am

Hi,
Everything Kruh has said is spot on but just to add to it, when you put the tube bach it would be prudent to vas or grease the thread its in a very wet area and
when you have finished setting it up, the grommet that just goes over the end of the cable, put some tape around the cable and grommet to stop rainwater running down the cable into the gearbox.
Wish you well Alan.
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Re: Clutch cable 250 ETZ

Postby Blurredman » Tue Nov 24, 2020 5:08 am

I would just loosen the clutch cable at the handlebar end fully,

then take the tach drive cover off,

Then turn the inner plate assembly anti-clockwise to tighten the cable

then re-install the tacho driver cover,

and then do the final adjustment at the handlebar. I tend to do it quite a bit tighter at the engine (and not to the 11mm specification) so that I don't have to do this adjustment quite so often at the engine- but instead at the handlebar. Also- I don't like the adjustment bolt being threaded out too far and only having a few threads inside the clutch handle assembly.
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1979 Suzuki TS185ER - 9,000 miles - Mud :)
1981 Honda CX500B - 91,000 miles - Long Distance :)
1987 MZ ETZ300 - 38,000 miles - Sun :)
1989 MZ ETZ251 - 49,000 miles - Commute :)

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Re: Clutch cable 250 ETZ

Postby Puffs » Tue Nov 24, 2020 6:10 am

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.
Last edited by Puffs on Tue Apr 04, 2023 6:34 am, edited 1 time in total.
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Re: Clutch cable 250 ETZ

Postby JawasandMZs » Tue Nov 24, 2020 2:39 pm

Clutch adjusted .. success! As instructed I knocked the plate behind the rev counter housing back a bit (anti-clockwise) using a hammer and large screwdriver.

Thanks to everyone who offered help. This was a typically quirky MZism - easy once you know but unless someone tells you, really hard to work out!
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Re: Clutch cable 250 ETZ

Postby Blurredman » Sun Nov 29, 2020 10:54 am

The clutch may wear very little. But MZ control cables are actually quite small and thin, from my experience, and what's more if you pay £1.50 for a cable then you're likely to experience at least a bit of stretch.
1973 MZ ES250/2 - 17,000 miles - The project! :)
1979 Suzuki TS185ER - 9,000 miles - Mud :)
1981 Honda CX500B - 91,000 miles - Long Distance :)
1987 MZ ETZ300 - 38,000 miles - Sun :)
1989 MZ ETZ251 - 49,000 miles - Commute :)

ftp://blurredmanswebsite.ddns.net/Vehicle_Documents/MZ_Documents/
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Re: Clutch cable 250 ETZ

Postby Kruh » Sun Nov 29, 2020 12:53 pm

Technically, that adjusment plate is not meant for adjusting cable tension.
Those 11 mm are there to ensure a specific gap between the thrust lever and the clutch thrust bearing. And the slack is then dependent on the cable tension and condition.

Image

Otherwise if thightened too much, the lever could keep pressure on the bearing (especially as the engine heats up). Which leads to wear or slight clutch slip. Or it could cause too much travel oh the thrust lever, because the initial pull (resistance) on the lever is just the spring thats on the arm.

Am I on the right track? I could be wrong. But I'm just thinking about it, why would MZ specify those 11 mm if you can also use that plate for cable adjusment?

Personally, I set the lever at the factory recommendation. Witha a brand new cable, there is plenty of adjusment left on the handlebar. If there is excesive slack, its probably due to poor quality cables.
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Re: Clutch cable 250 ETZ

Postby nice2day » Mon Nov 30, 2020 4:37 am

Hi Kruh. The factory recommended setting is to set the internal operating lever that the cable pulls to just over 90 degrees relative to the pull on it from the cable. This ensures the pull occurs at right angles and is the most efficient angle to maximise the effort and thus the lightest "action" at the lever and the correct gap between the lifting mechanism and clutch thrust bearing. The gap of the pressure mechanism will increase as the clutch plates wear and the internal lever angle will also increase moving it past the 90 degree position. You then adjust the back plate to bring back the setting to 11mm thus setting the internal lever to the optimum levering position. This also corresponds with the correct gap between the pressure bearing and the clutch hub and ensures the pressure bearing is not constantly loaded.

The two criteria are interlinked.
When the setting is 11mm:
1) the INTERNAL lever angle is set correctly
2) the free-play gap of the pressure mechanism is also correct.*

This is set by moving the rotating Back-Plate....tightening the cable slack does NOT adjust the clutch action....just the cable slack

*This is known because the rotating action of the thrust mechanism is converted to a linear (IN-OUT) movement by the spiral of which the pitch is known. Thus a known angular rotation is converted to a known linear thrust movement and thus the gap can be predicted.

BOTTOM LINE: The 11mm setting must always be kept to. If the cable slack cannot be removed at the lever end then the cables inner wire has an incorrect surplus in relation to the outer sheath and must be addressed.

Les
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Re: Clutch cable 250 ETZ

Postby Kruh » Mon Nov 30, 2020 8:52 am

Thanks for this very detaild explanation.

I was on the right track then.
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