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Discussion Starter · #1 ·
Hi all - just finished a teardown on an 05 R6 as the 2nd gear failed inside the transmission. While I had the motor out, I made the mistake of turning it upside down before taking the head off. When I finally took the head and camshafts off, I noticed 3 of the magnetic shims underneath the followers had popped out of its cavity in the valve spring (the 3 followers were noticeably taller than the others). I put the shims back in and followers on top then buttoned it all up. Finally came to realize that the manual says to keep the numbers on the shim facing UP. I can’t remember which direction I put these 3.

Flash forward a couple weeks, I got the motor back in and it runs/drives great. After about 45 mins of riding, I got it up to highway speeds and following that I started to notice a ticking noise that wasn’t there during the first 45 mins. Now the ticking noise is barely noticeable at idle but very clear at any speeds.

My questions: are these shims magnetically “polarized” such that they stay with the follower buckets? Could I have put a shim upside down which means it’s repelled from the follower and could have jumped out of the valve spring cap? Or is this ticking noise possibly just the “Yamaha Tick”?

Thanks kindly in advance for any help or guidance.
 

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YZFR6... ooodles of HP
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Orientation of the shim will only help or prevent the mark from wearing off with use. The valve spring will not allow slack at any point other then when the valve is fully seated. Hence the lash dimensions. Did you properly check them?
 

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Discussion Starter · #3 ·
Orientation of the shim will only help or prevent the mark from wearing off with use. The valve spring will not allow slack at any point other then when the valve is fully seated. Hence the lash dimensions. Did you properly check them?
Thanks for the response! I didn’t check lash or valve clearance since I wasn’t in there for head work, just the transmission. I didn’t even remove any valves, only pulled the followers off a couple that were clearly taller than the others due to flipping the motor upside down with the head installed still. This caused enough space for the shim to pop out of its holder.

Glad to hear the magnetic shims aren’t polarized.
 

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Uh, the shims are not only not polarized, they aren't magnetic. Just shims.

Edit: steel is 'magnetic' in the strictest definition. The steel shims are not magnets however, they have no magnetic charge themselves, they simply react to magnets because they are ferrous.
 

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YZFR6... ooodles of HP
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Cam rotation determines the amount a valve is open. The chances of more than a few of the 16 being fully closed is why they appear "taller." The shim can't go anywhere because of the bucket!
 

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Cam rotation determines the amount a valve is open. The chances of more than a few of the 16 being fully closed is why they appear "taller." The shim can't go anywhere because of the bucket!
The lobe determines the lift and duration of the valve being open, not the rotation. They don't open further with rpm or anything.
 

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YZFR6... ooodles of HP
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For purposes of visually some valve stems length visible being longer is due to the cam location. NOT rolling the block upside down. Obviously this guy doesn't need cam lobe height and duration confusing him. Iron will stick to amagnet. That does not mean magnetic. Magnetic holds magnetism and will stick to day your refrigerator door.
 

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Discussion Starter · #9 ·
Cam rotation determines the amount a valve is open. The chances of more than a few of the 16 being fully closed is why they appear "taller." The shim can't go anywhere because of the bucket!
I took the cams off so the shims could pop out of the retainer and sit between the follower bucket and the valve spring cap
 

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Not true, the shims and followers are both magnetic. I pulled them off with a magnet
Uh, they're steel. So, you can use a magnet on them. They are not magnetic in the sense that they have polarity. They are not magnetically charged. They are just steel shims.
 
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