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Farkle Purchasing System
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Discussion Starter #41
This is just a wild guess, but if your slave cylinder is already a used replacement with unknown history, then it could (in theory, of course) be that the SC piston is worn just enough to rock back and forth and start to get cocked sideways in its housing and bind up that way. Not very likely, I know, but it sounds like everyone is starting to grasp at straws here, and I figured I'd put the possibililty out there... shrugs his shoulders :geek:
Yes, that's what I'm thinking. No idea how many miles were on the used SC, but the paint was starting to wear off, so I'm guessing several years' worth at least.

Only real fix would be a new SC. Sucks cost-wise, but I don't want to have to do this again in another 30k miles.
 

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Could also check the surfaces where the SC piston meets up with the clutch pushrod. See if either or both of those are still smooth and square, or if one of them is chewed up and/or wonky in other ways. I don’t remember how those fit together anymore, so I might just be blowing smoke with this one...
 

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Farkle Purchasing System
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Discussion Starter #43
Basically there's a cylindrical depression in the middle of the piston. Clutch pushrod goes in the little pit in the middle and is a bit rounded on both ends, so you can install either way.

No irregularities there to make anything bind. I greased the piston end of the rod just for giggles.
 

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If you have a heavy spring you could set the SC in a G clamp and push against the spring.

That would test the hydraulic system for irregularities, if none are found it could be in the gearbox.

I recently customised a air head BMW and had problems with the brakes, turned out to be one of the hoses, the G clamps and old valve springs told me the story.

It would depend on feel but applying and releasing pressure changing things could point to the MC

It is very common for dirt bikes to wear low spots into the clutch basket, it then takes a bigger effort to get the plates out of the hole, leaning the bike to the left and removing the clutch cover could reveal something amiss ?
 
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Farkle Purchasing System
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Discussion Starter #45
I do have a G clamp, but not a sufficiently heavy spring. Can probably get one.

Sure seems worth the effort. A new Suzi SC assembly is about $100 shipped. If I can observe the piston binding, that will be super helpful.
 

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Just to muddy things up. If you can improvise a pivot point so that you can use something like a tire iron to push the clutch rod in, you can push the clutch rod in repeatedly and see if you can find a problem there. You would have to be very strong to push the clutch rod in by hand as you are compressing all the clutch springs at once. see if you can find a pivot point and a lever to push the clutch rod in repeatedly. if there is an intermittent problem then the problem is in the clutch. if no problem is found there then the problem is def in the hydraulic system.
and you don't need a special tool to remove the clutch basket. the basket is splined onto the trans input shaft right? put it in high gear, apply rear brake, and apply 2 foot breaker and socket to basket nut and loosen or tighten as needed.

Cheers

RLBranson
 

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Farkle Purchasing System
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Discussion Starter #47
Springs obtained. Going to find out whether the SC will bind when I'm watching.

If it doesn't, problem must be in the clutch itself.
 

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Discussion Starter #48
Great news! I've likely solved the mystery. Seems the SC piston is binding at times.

Got the strongest spring I could find that would fit (details below), put SC in a G-clamp with the spring against the piston, so as to push it back against clutch lever action.

Spring was rated for over 80 lb. With normal clutch lever feel, it could slowly push the SC piston back after lever release.

Eventually, I got the "sticky" lever feeling again. In this case, piston was not able to be pushed back by the spring.

The piston wasn't obviously cocked at an angle, but it wouldn't take much for it to bind. Seems clear I need a new SC.

Either the piston has worn (where did the metal go??), SC housing has warped, or both to some degree, and the piston is sometimes binding against the housing.

If you want to replicate my test setup at home, you can use a spring from the Hillman hardware assortment, which I believe is stocked by TrueValue stores as well as Ace.

I'm unsure of the model numberl, but it is a compression spring (obviously) about 17mm in diameter, 35mm long, made of ~2.5mm wire.

This spring fits perfectly into the depression on the clutch side of the slave cylinder piston, which helped testing a great deal.
 

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So my ideas do work sometimes, I must tell my bride....
 

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Farkle Purchasing System
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Discussion Starter #50
Right now Partsoutlaw.com (online parts dept. of DeLand Motorsports in Florida) has the best price on the SC assembly - about $10 cheaper than anyone else.

They're still honoring last year's $4.99 shipping code (OUTLAW19) so I saved a good $15 vs. buying anywhere else.

Not the fastest source - will probably take a full 2 weeks to get the part, but then again OEM parts seem to always ship slow.
 

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Discussion Starter #51
somewhat related dumb question: Does anyone sell G-clamps with built-in wooden or plastic contact points/blocks?

When testing the SC with the G-clamp, I used small blocks of wood between the clamp & SC to distribute the force, & avoid cracking the SC housing or marring the piston. However, the blocks were constantly trying to slip out of place. Maybe there is a simple, free or cheap solution to that, which I've overlooked?

I tried taping the wood blocks in place, but that didn't really work.
 

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somewhat related dumb question: Does anyone sell G-clamps with built-in wooden or plastic contact points/blocks?

When testing the SC with the G-clamp, I used small blocks of wood between the clamp & SC to distribute the force, & avoid cracking the SC housing or marring the piston. However, the blocks were constantly trying to slip out of place. Maybe there is a simple, free or cheap solution to that, which I've overlooked?

I tried taping the wood blocks in place, but that didn't really work.
I my case I have bent some alloy strips that fit over the solid side of the clamp, some of the strips have rubber or plastic glued to them.

On the screw side of the clamp I have made buckets out of plastic caps, some with stuff stuck or bolted to them.

When I did the spring test I removed the flat plate from the screw side of the clamp, I added a washer, this allowed the spring to slip over the pin left when the plate was removed helping the secure the spring in place.

Just tape nothing else can be helpful.

After building what I need to get the job done I put them to one side and may adapt them for my next job.
 
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Discussion Starter #54
Great news - new SC shipped today! Should be here by next Thursday.
 

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Discussion Starter #55
Today's the day! Today's the day!

New clutch should be delivered this afternoon.

Going to install it ASAP, will report whether it fixes problem.
 

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Discussion Starter #56
JFC, a break cannot be caught.

New clutch release cylinder installed. Didn't fix the problem.

No idea what else to do, so I suppose it's time to replace all moving bits from one end to the other. Piston cup set, as well as the pushrod & bushing that touch the clutch lever, all new ones ordered.

I'll replace the hose last, as it seems like the least-likely cause of the issue.
 

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Since the slave cylinder didn't change anything.....
And this is an unusual problem......
Go back to what is different. The hydraulic hose. I know Galfer is a good brand. But it isn't a factory Suzuki part and in my opinion is still suspect.
 

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Just by chance (and I know you have checked it over and over again, Desert)……..are you running Chinese Levers (either shorty or long)?? I saw on ADV rider that a Rider was having problems with his $21 levers.....it literally locked his front brake while passing a car.
If you are running the Chinese versions, maybe try an OEM Lever if you have a spare...….???? (easy box to check off??)
 

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Discussion Starter #59
No, OEM lever. I never saw the sense in using the cheapest thing available for a safety-critical control.

Same reason I shied away from the $30 Chinesium footpegs.

It will take 10 days or so to get the parts. Which, really, isn't bad - DeLand Motorsports (aka Partsoutlaw) is smashing it lately. In the meantime, I'm going to take the lever off and see if there's a burr I missed or something like that. Maybe slather all the moving bits (that are outside the clutch MC) in Mobil 1 grease.

Sure thought it was the slave cylinder binding, but obviously it wasn't.

Not that mad. I guess I can sell the used SC and recoup a few bucks. It's in fine shape. I don't know that it's actually possible to "wear out" the SC, assuming normal maintenance.

(The truly maddening part of this is how random it is. I'll get 20 good clutch lever pulls, then it fights me. Sometimes it won't feel crunchy until almost fully in.)
 

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Eliminate the clutch itself as the problem or find the problem is in the clutch by using a lever to push the clutch rod in repeatedly. see if there is an occasional glitch doing that.

RLBranson
 
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