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yellow_cad

Clutch on my OSSA MAR gets stuck every winter

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I use F type atf in the gear box, but every year my clutch gets very stuck.  Any ideas for getting it unstuck right now and keeping it from sticking each winter would be greatly appreciated.  Thanks

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As for getting it unstuck, driving with the clutch lever pulled in may work, but when the clutch releases abruptly it will almost send you over the bars (don't ask me how I know).

Disassembly will unstick it.

Dimpling the steel plates completely fixed that problem on my Shercos.

Dimpling Setup.JPG

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10 hours ago, yellow_cad said:

I use F type atf in the gear box, but every year my clutch gets very stuck.  Any ideas for getting it unstuck right now and keeping it from sticking each winter would be greatly appreciated.  Thanks

Only every winter ?  

you are very lucky , mine gets stuck every time I ride it !

If I ride it today , it will definitely be stuck tomorrow . in fact sometimes just letting it cool down for an hour is enough for it to stick.

as for releasing it,    as has been said - bump start it and ride it while pulling in the clutch is one method that usually works for me in a few minutes.

or pull in clutch and keep kicking over till it releases ( ignition off ) 

perhaps you could hold the clutch lever in with a cable tie ?     when not using the bike 

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Another thought... I suspect new steel plates may work better.  With my Shercos, the sticking behavior did not start until the clutches had a lot of hours on them.

Since you're already using ATF, it might be worth trying a different type.  Valvoline Dexron-VI is an inexpensive full synthetic that has been suggested as a substitute for the very expensive Elf HTX 740 gearbox lube used in the Montesa 4RT.

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Short term fix that's easy - After every ride, I park the bike and put a piece of velcro strip on the bars, holding the clutch lever engaged.  Come back, take off the strip, and life is good!

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konrad

Thanks for that picture of how dimple.  Can you share details on diameter and depth?  Do you use a CNC or are you super patient?

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Definitely not super patient.  It was done on a late 1980s CNC machine with a "conversational" programming aid.  The bolt hole circle subroutine allowed a maximum of 99 holes -- so that's what I did.  Still, that's nearly 2000 dimples for a set of 5 steels.  I used a #3 center drill, but I don't think the dimensions of the dimples are at all critical (and I could not tell you what they are at this point).

I was amazed how well it worked.

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10 hours ago, robbiesty175 said:

Short term fix that's easy - After every ride, I park the bike and put a piece of velcro strip on the bars, holding the clutch lever engaged.  Come back, take off the strip, and life is good!

I just bought a bike that had been sitting for 15 years straight with the clutch lever held in with cable ties because the owner didn't like it to stick. The clutch works perfectly

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Yes sir, mine will stick at the beginning of the next ride.  I find it best to roll the bike, engine running, in neutral, as it is rolling, pop it i to gear.  Then ride a bit until it releases.  Normally pretty quick.

 

On a side note, my buddies MAR, I just rebuilt his motor and gearbox.  He installed new plates and trials clutch springs, plus polished the clutch release shaft.  He already had a MSR lever.  Have not ridden it yet, but suffice to say his clutch pull effort is as light, maybe even lighter than his 17 Sherco.

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On 5/5/2019 at 9:22 PM, robbiesty175 said:

Short term fix that's easy - After every ride, I park the bike and put a piece of velcro strip on the bars, holding the clutch lever engaged.  Come back, take off the strip, and life is good!

 

On 5/6/2019 at 7:32 AM, feetupfun said:

I just bought a bike that had been sitting for 15 years straight with the clutch lever held in with cable ties because the owner didn't like it to stick. The clutch works perfectly

Does'nt that put a set on the springs?

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6 minutes ago, thai-ty said:

 

Does'nt that put a set on the springs?

If spring steel yields over a long time period when loaded below it's yield stress limit, then yes.

Bear in mind that clutch springs only carry slightly more load when the lever is in than when it is out, so it probably doesn't make much difference to how long the springs last storing the bike that way.

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14 minutes ago, feetupfun said:

If spring steel yields over a long time period when loaded below it's yield stress limit, then yes.

Bear in mind that clutch springs only carry slightly more load when the lever is in than when it is out, so it probably doesn't make much difference to how long the springs last storing the bike that way.

Thanks.

Might give it a go on both my ty mono's then as they are forever sticking when put away for a week or more.

yeah, yeah i know - ride them more often.....

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I find that putting it in 4th gear and rocking it back and forth with the clutch in (engine off) typically frees it up... but I like the Velcro idea.

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