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Discussion Starter #1
I think the tappet clearance is out of spec on my bike (getting alot of noise and i think it's the tappet clearance). I found out that suzuki was stupid with their motors and requires the replacement of a shim to adjust this clearance vs torquing a bolt like honda motors. I was eyeing what all had to be removed to accomplish this if I do have to replace the shims and I noticed the tensioner for the rear cylinder is in a really precarious spot behind the frame. Is there a trick to removing that easily or is it just part of the fun of replacing the shims?
 

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Show me a modern bike that DOESN'T use shims! Yes, even Honda.

In fact, it's very common to use Honda shims because they are available in finer increments (0.025mm vs. 0.05mm) than other brands.

As for the rear tensioner: yes, it's a pain. (I'm in the middle of doing my valve adjustment / cam swap right now, oooooh loads of fun, I have scraped hands to prove it). You need to remove the right rearset to better access the CCT. I have found that removing the fuel tank also helps you see what you're doing from above. A long 5mm T-handle allen wrench is what I used for those two bolts.
 

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Also, check the valve clearance interval. Screw adjust valves require a 600 mile adjustment, along with adjustments every few thousand miles (depends on the bike). The SV doesn't even need you to look at valve clearance until 15k miles. Often, they are still fine after all those miles.

I think the shim type have a lower mass which affects valve function at higher RPM. The screw type are easier to adjust as they don't require removal of the cam...

Different designs for different engines. I wouldn't fault the designers. They knew exactly what they were doing.

So, take your pick. I've got both types. They both go "vrooom".
See ya
Mikemo
 

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shim under bucket are much more reliable way for valve lash to remain within tolerance than locknut & screw
 

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Discussion Starter #6
Ah i didn't know it was more reliable like that. I was more referring to honda car motors since i've taken a bunch of those apart and they're all adjusted similarly. So when I do this this...if i have to replace the shim wouldn't the OEM shim work? I mean, I don't have to play test a couple different sizes to get it within spec...the OEM one should do that for me i presume?
 

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SiFactor said:
So when I do this this...if i have to replace the shim wouldn't the OEM shim work? I mean, I don't have to play test a couple different sizes to get it within spec...the OEM one should do that for me i presume?
Not sure exactly what you're asking. First you need to figure out what size you need to get it within spec, and THEN you can decide if Suzuki OEM will get you "close enough", or if you would prefer a Honda shim to get you closer.

Intake clearance spec: 0.10 - 0.20 mm [Preferred: 0.15mm]
Exhaust clearance spec: .20 - 0.30 mm [Preferred: 0.28mm, looser side is better]

A = Replacement shim thickness
B = Measured gap
C = Desired gap
D = Existing shim thickness

A = B - C + D

Here's an example from my valve adjustment after cam swap:

Measured 0.127mm clearance on rear exhaust valves. I wanted 0.28mm. Existing shim was 1.70mm.

A = 0.127 - 0.280 + 1.70 = 1.55 ----> 155 shim

In this case, a Suzuki OEM shim was fine. However, if my desired gap called for, say, a 152.5 or 157.5 shim, a Honda shim would have been preferred, since they are available in those sizes.

Measure all your gaps, then decide which shims you need for each. Then go to the dealer. If possible, have them mic each one to make sure they are the thickness that they indicate. I've seen a few that have been off.
 

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Discussion Starter #8
Okay...that makes sense. I was thinking that since you pull the old shim out and replace it with a new one, the OEM shims should bring it back to spec (so it would seem logical) but I guess that's not always the case?
 

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Correct. You are replacing the shim not necessarily because the shim itself is wearing down (on our bikes it sits under the bucket after all), but more likely, to account for changes in dimensions / wear of the other valvetrain components over time.
 

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Discussion Starter #10
ah okay, it's all clear now. I don't think I have a micrometer so I probably should get one before doing this to determine what the thickness of the old shim is, right?
 

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Occasionally the number is worn off if the shim was installed number side up, in which case a micrometer will tell you the thickness. But otherwise I've had the numbers legible even after 30,000 miles.

What helps with that rear cam chain tensioner is a very long "ball" hex socket. They aren't square like a normal hex (allen) socket, but somewhat round, which lets you turn the fastener without being square to the fastener head. That way you can go in at an angle.
 
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