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Hey everyone, I'm just finishing up my valve job and I noticed something strange. I replaced 5 shims that were out of spec, but the clearance for 2 of them (same valve exhaust side) stayed the same. The others are all in spec now but these to stayed at around 0.015". Anyone know why this might be?

Not all valves change. Some can stay and some can change. Thats just they way it goes.

I did the valves at school last week on a 02 R6 and I had two valves remain the same as well.

So.. i just leave it? Can I do anything to fix that?

What is spec for that one?

Specs: Exhaust (0.008~0.012”)

2 Valves: 0.014 & 0.015"

spizzak wrote:Specs: Exhaust (0.008~0.012”)

2 Valves: 0.014 & 0.015"

You need to shim them and add 1.0 to the shim that was in there.

For every thousanths you need to add .05

I'm not sure what you mean. Could you explain in a bit more detail? I believe I have 160 shims in there right now.

spizzak wrote:I'm not sure what you mean. Could you explain in a bit more detail? I believe I have 160 shims in there right now.

ok,

Specs: Exhaust (0.008~0.012”)

2 Valves: 0.014 & 0.015"

You need to bring the .014 down to .008--------thats a .006 difference. You need to add .05 per every .002 = 1.5 added to your 160 shim = 161.5

okay I got you, but 0.05 x 3 = 0.15 not 1.5 .. I'm not sure if one of those is a mistake. So basically I have to re-readjust the shim? Do you know why it didn't do anything the first time I did that?

This may help.
http://www.logicminds.biz/motorcycles/shimulator.html

The shims are in mm, numbered in 100ths of a mm; a #160 shim = 1.60mm. You're measuring in inches. Convert your clearance to mm (in * 25.4 = mm), do the math, determine the new shim size.

.014" - .012" = .003"
.003" * 25.4 = .076 mm increase in shim thickness = +7.6 shim number. Shims are in 0.05 mm / 5# increments, so go up 10#. In this case, from #160 to #170.

I've been told by many that it's better to run the clearances loose. You get a better valve seal = better power, and the clearances last longer between necessary adjustments. That's why in the example above I based it on the .012" / 0.30 mm max clearance, not the tighter 0.008" / 0.21 mm min clearance.

Good luck!

spizzak wrote:okay I got you, but 0.05 x 3 = 0.15 not 1.5 .. I'm not sure if one of those is a mistake. So basically I have to re-readjust the shim? Do you know why it didn't do anything the first time I did that?

Your right .015

I was on the phone and writing. LOL That could have been ugly.

DonTZ125 wrote:The shims are in mm, numbered in 100ths of a mm; a #160 shim = 1.60mm. You're measuring in inches. Convert your clearance to mm (in * 25.4 = mm), do the math, determine the new shim size.

.014" - .012" = .003"
.003" * 25.4 = .076 mm increase in shim thickness = +7.6 shim number. Shims are in 0.05 mm / 5# increments, so go up 10#. In this case, from #160 to #170.

I've been told by many that it's better to run the clearances loose. You get a better valve seal = better power, and the clearances last longer between necessary adjustments. That's why in the example above I based it on the .012" / 0.30 mm max clearance, not the tighter 0.008" / 0.21 mm min clearance.

Good luck!

People bring their bikes in because the valves chatter. Thats because of the clearance. I was told to bring them down to spec to tighten the clearance and no more noise. You may be right about the loose clearance - better valve seal. I believe that. As long its within spec though.

Absolutely - as loose as the spec allows, but no more.