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Discussion Starter #1
So, I replaced the clutch right before my last race weekend and noticed that Ref #17 in the following diagram had no fingers left (all 3 of them):
http://www.ronayers.com/Fiche/TypeID/26/Type/CLUTCH_/MakeID/4/Make/Yamaha/YearID/47/Year/2006/ModelID/1709/Model/YZFR6V_R6/GroupID/336366/Group/CLUTCH_

The previous owner said the slipper clutch mod was done, removing the fingers on two of the springs. I found the 3rd spring with NO fingers left, and the fingers floating around next to it seemingly broken off. I removed the broken fingers (now basically 3 washers on this part of the bike) and put the clutch back together.

Ran it over the weekend and won my races... now a little late, trying to figure out what I need to do about these spring fingers? Clutch worked great all weekend and the slipping on downshifts was just about perfect. Do I need to install a new Ref #17 spring? or Two? or 1.5... :D What is not having these springs going to do to the bike?

Details:
06 r6r
slipper clutch mod
Race bike
Seems to work fine now
 

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"The Dude abides .. "
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you must have ONE of those 3 springs with fingers. You can't run 3 "washers" .. you need 1 complete. You can cut fingers off the other 2 if you want. Or a combination of the 3. Some will cut 6mm off the middle spring fingers, and 12mm off the top spring's fingers.
But you can't run 3 round washers (no fingers on any of the 3). The ramp style slipper clutch can not operate without the "Y" spring in place pushing on the center hub.
 

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But you can't run 3 round washers (no fingers on any of the 3). The ramp style slipper clutch can not operate without the "Y" spring in place pushing on the center hub.
But it sounds like he did. And not only did he run it with three washers having no fingers, he won his races.

So what is the consequence? Catastrophic failure obviously did not occur. Accelerated wear? Decreased slipper clutch performance?
 

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"The Dude abides .. "
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But it sounds like he did. And not only did he run it with three washers having no fingers, he won his races.

So what is the consequence? Catastrophic failure obviously did not occur. Accelerated wear? Decreased slipper clutch performance?
1st off, why did the springs break off. My guess is he did not center the nut in the y-spring. When you tighten the center hub nut and don't first ensure the collar of the nut goes into the springs (or spring and washers if you cut springs), you smash the "Y" springs. There are also locating tabs on each of the 3 springs in the center that need to go into the 3 grooves of the center hub. Again, those can break off if not installed correctly.

If you don't understand how the ramp style center hub works against the clutch basket, look at a detailed exploded view..
Without 1 spring in place, you have a slipper clutch that will not work, and who knows what else.. I would tell you what it could do, if anyone didn't run the springs the way you are supposed to do.. but we don't.
You could run a race with no body work, but why would you do that ? You could run with an extra metal plate in the clutch stack putting the stack height beyond spec, but why would you do that?? So just because he won his races does not mean that you should CONTINUE to run the clutch without at least one clutch spring and the 2 washers (with fingers cut off) in place.
 

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"The Dude abides .. "
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and because i can't let well enough alone :) here's the "why" ya can't (or should i say shouldn't) run with no springs.. the slipper will NOT work, and without the spring to keep the hub down even when there is no backtorque applied, the hub could jump.

I don't have a spare basket layin around, but this is the center hub, and all the grooves around the outside is what metal plate grooves ride on and drive with. The "Y" spring with a nut on top holds the hub DOWN when there isn't backtorque being applied (backtorque is applied when you decel).




Here is the underside of the hub showing the 3 "ramps" that interfaces with 3 opposing "ramps" of the clutch basket.. you can CHANGE the rate at which the clutch slips by:
1) altering the # of "Y" springs.
2) altering the # of "Y" springs AND using shims to hold down or raise them.
3) alter the stack height of the clutch stack.
4) alter the clutch pressure plate springs (go from stock to kit springs-firmer)

but YOU HAVE TO HAVE 1 of the "Y" springs in place to hold the center hub down when you are ON the gas..

 

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Discussion Starter #7
and because i can't let well enough alone :) here's the "why" ya can't (or should i say shouldn't) run with no springs.. the slipper will NOT work, and without the spring to keep the hub down even when there is no backtorque applied, the hub could jump.

I don't have a spare basket layin around, but this is the center hub, and all the grooves around the outside is what metal plate grooves ride on and drive with. The "Y" spring with a nut on top holds the hub DOWN when there isn't backtorque being applied (backtorque is applied when you decel).




Here is the underside of the hub showing the 3 "ramps" that interfaces with 3 opposing "ramps" of the clutch basket.. you can CHANGE the rate at which the clutch slips by:
1) altering the # of "Y" springs.
2) altering the # of "Y" springs AND using shims to hold down or raise them.
3) alter the stack height of the clutch stack.
4) alter the clutch pressure plate springs (go from stock to kit springs-firmer)

but YOU HAVE TO HAVE 1 of the "Y" springs in place to hold the center hub down when you are ON the gas..

Want to sell that Y-spring you got there? :D
 

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Discussion Starter #8
1st off, why did the springs break off. My guess is he did not center the nut in the y-spring. When you tighten the center hub nut and don't first ensure the collar of the nut goes into the springs (or spring and washers if you cut springs), you smash the "Y" springs. There are also locating tabs on each of the 3 springs in the center that need to go into the 3 grooves of the center hub. Again, those can break off if not installed correctly.
Ive had this bike a month now and that was the first time I had the clutch open... prior owner probably did one of those :
 

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"The Dude abides .. "
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Want to sell that Y-spring you got there? :D
negative .. LOL.
funny enough they were apparently on back-order recently .. Eddie Craft, a pro racer from up north, desperate to get some for a rebuild he had just done, called me and i sold him my spares. It took a couple weeks to get my spares replaced. :) I run 2 full, and 1 with 12mm cut (that cut one goes on top) but I like a good deal of engine braking. I know a number of racers that run 2 fully cut, with only 1 full. Again, you can put the full one on the very bottom with 2 "washers" (remainder of cut springs) on top (little more engine braking) or reduce the spring tension by putting a washer under the full spring.. but ya gotta run all 3 pieces, cut or otherwise.
 

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"The Dude abides .. "
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just make sure ya take time to instal em right. it's easy to not get the collar of the nut into the 3 springs. then torque to spec, and peen the thing to the crankshaft.
while at it, measure stack height.. and if you do remove the center hub, be sure you instal it correctly. there is a wrong way it goes in.. and if the center hub is in wrong, those ramps (pictured above^^ ) won't ride up the oposing ramps of the clutch basket. It will just rock forward-backward but won't allow the clutch to SLIP ;)
Then be sure ya offset the outer fiber, and line up the pressure plate as the manual shows.
nothin to it.
 

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Discussion Starter #13
just make sure ya take time to instal em right. it's easy to not get the collar of the nut into the 3 springs. then torque to spec, and peen the thing to the crankshaft.
Can You explain this a little more? I understand the rest though.
 

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"The Dude abides .. "
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this collar has to go inside the circular part of all 3 "Y" springs. It does not do it by itself, the 3 springs stacked up will fall onto the crankshaft. If you run this nut on there without lifting them and allowing this collar to go INSIDE those 3 springs, it will smash em flat. Bad.


the outermost part of the center hub nut is just like your counter shaft lock nut, you have to use a screwdriver or something to hit it into the recess on the end of the crankshaft, just like you peen the nut on the countershaft to lock it in place after you torqued it down.



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Hi guys I am looking to do this mod to my 2018. - trying to do my research first. I am looking to get an increase over the stock clutch but nothing too crazy. do you recommend washer, ramp spring, washer set up? or should i go with ramp spring first, followed by two washers after?

any help would be great

thanks !
 
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