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It was time to replace my clutch friction and steel plates so I went with the "TB Parts clutch and hd spring kit" which came out to like $40. I was running 3 Koso 60% clutch springs and 3 EBC 15% springs with a chimera lifter plate. Installation was smooth. Started the bike and then as soon as i put it in gear my bike stalled. After reinstalling the clutch basket 4 times trying to get a diagnosis my friend recommended that it could be that the clutch springs were too stiff. So we took it apart one last time and swapped out TB parts clutch kit for SMR kit and used EBC 15% springs all around and problemed solved. Thank God it wasnt a serious issue! I was so stressed trying to figure this one out.

So we came to the conclusion that the TB Parts clutch kit wasnt made for stiff springs. Probably the reason they come with 10% clutch springs. Maybe anything above 15% could cause some clutch problems? So if you run into this issue try bringing spring % down and see if that works. Thats all we could come up with...

Has anyone else had this issue with with TB clutch kit?
 

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Yes, I have the SMR with 30% springs. It will stall or slam if I don't free the clutch plates by rolling it in high gear with the lever in before starting. With my 79 Bonneville I could use the kick starter馃槉
 

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I had this exact problem with the Koso 60% springs. I installed them with the koso plates/discs, and a chimera lifter plate. Soon as you put it in gear it stalled. Rebuilt and installed it maybe 5 times before ordering the SMR 60% springs. Now with those in, everything works like it should and the new setup feels awesome.


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Can someone explain how putting the bike into gear with stiffer springs and the clutch lever pulled all the way in could cause a problem?

If the clutch lever is pulled in and the cable is adjusted properly, the lifter plate should be relaxed off of the plates enough to allow the engine to keep running.

The problem sounds like there was too much slack on the clutch cable so that when pulled in, with stiffer springs, the plate was not lifted enough.

I find that the grom clutch cable cable linkage and assembly is a bit finicky. Witch 60% stiffer springs, there is a fine line between not having enough slack to prevent the engine dying when engaged clutch lever pulled in, and too much slack so that the clutch slips under load.
 

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If you look at the Koso springs next to the stock springs and next to the SMR springs, the Koso have 1 extra coil. My guess is when the plate is installed the springs are bottoming out of themselves, not allowing for any travel...like when you pull the clutch lever. Never looked at the Koso springs when installed to verify that though.

I tried adjusting the cable for about 2 hours and was pulling my hair out the whole time thinking I鈥檓 insane lol. Once the Koso springs where switched for the SMR, it worked.


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Well, I had my engine clutch side case open today to replace the stock clutch with an SMR heavy duty clutch and was putting the Koso lifter plate and 60% springs in place.

Torqued the 3 bolts to 12Nm as per the manual and this happened. Pics attached.

Been running the Kosos 60% springs flawlessly for about 1000 miles. I wonder if this failure was due to using stiffer springs and upgrading the motor with a TB cam producing more power. The reason I was upgrading the clutch was due to the OEM clutch wearing out and slipping under max load. About 1000 miles on the clutch basket with the Koso 60% springs, TB cam, hindle exhaust and aracer tune. Pretty much WOT most of the time.

Placed an order for the new pressure plate and a set of SMR 60% springs to compare with the Koso spring I already have.



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While you are down and going through the trouble, have you thought about doing the six bolt clutch mod? You can tap the other three post and use a Chimera plate with 3 more factory bolts to more evenly distribute the load. Couldn't hurt.
 

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That is a great idea actually. Thanks!

While you are down and going through the trouble, have you thought about doing the six bolt clutch mod? You can tap the other three post and use a Chimera plate with 3 more factory bolts to more evenly distribute the load. Couldn't hurt.
 

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Torqued the 3 bolts to 12Nm as per the manual and this happened. Pics attached.
That usually happens if the clutch center and basket are not aligned correctly, it's easy to get wrong as it looks good but both parts are not seated correctly, if that makes sense... Had it happen once, now I mark both parts and install in the same position.
 

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That usually happens if the clutch center and basket are not aligned correctly, it's easy to get wrong as it looks good but both parts are not seated correctly, if that makes sense... Had it happen once, now I mark both parts and install in the same position.
He is correct, it will only line up correctly in a few different spots. Check alignment empty and mark it, then add disc and plates.
 

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That usually happens if the clutch center and basket are not aligned correctly, it's easy to get wrong as it looks good but both parts are not seated correctly, if that makes sense... Had it happen once, now I mark both parts and install in the same position.
He is correct, it will only line up correctly in a few different spots. Check alignment empty and mark it, then add disc and plates.

Indeed a good point. I am aware of that potential issue and did in fact mark the basket and plate alignment .

The basket will fit the plate in 2 possible positions 180 degrees opposite from each other. Even without marking the basket, if you line up the metal spacer plate extensions with the splines in the pressure plate, and make sure the groove on the edge of the basket has a clear channel to be inserted, it is possible to get the basket seated without too much trouble.

Any links to how well the 6 bolt pressure plate mod works? Any how too's?
 

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I'd recommend 6 of the same bolt either stock or aftermarket to keep the weights as similar as possible. I'm sure it is still fairly balanced but at this stage why not take the extra precaution? These bikes vibrate enough already, lol.
 

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More things to experiment with. Placed an order for this slipper clutch kit.

Seems to have a better pressure plate.



 

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Got mine a few days,,, comes with six hole plate as well as the proper bolts... be vary aware of torque spec.

Also ordered the 6 hole chimera cnc lifter plate to try with the Takagawa slipper clutch pressure plate that has 6 threaded holes, instead of their kit cast plate, but It may be too thick to work. We shall see.

 
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