Valve Clearance Calculator

Exhaust Valves

(mm) ~ (mm)

Left Exhaust Valve

New Shim Number: {{exctrl.l.newpillnumber}}
{{exctrl.l.newpillnumberhigh}} ~ {{exctrl.l.newpillnumberlow}} ( {{exctrl.l.newpillmmhigh}}mm ~ {{exctrl.l.newpillmmlow}}mm )

Right Exhaust Valve

New Shim Number: {{exctrl.r.newpillnumber}}
{{exctrl.r.newpillnumberhigh}} ~ {{exctrl.r.newpillnumberlow}} ( {{exctrl.r.newpillmmhigh}}mm ~ {{exctrl.r.newpillmmlow}}mm )

Intake Valves

(mm) ~ (mm)

Left Intake Valve

New Shim Number: {{inctrl.l.newpillnumber}}
{{inctrl.l.newpillnumberhigh}} ~ {{inctrl.l.newpillnumberlow}} ( {{inctrl.l.newpillmmhigh}}mm ~ {{inctrl.l.newpillmmlow}}mm )

Right Intake Valve

New Shim Number: {{inctrl.r.newpillnumber}}
{{inctrl.r.newpillnumberhigh}} ~ {{inctrl.r.newpillnumberlow}} ( {{inctrl.r.newpillmmhigh}}mm ~ {{inctrl.r.newpillmmlow}}mm )



1) Look up the spec settings for your bike's intake and exhaust valve clearance ranges.
(Don't trust the internet - Go get your bike manual!)

2) Measure the current clearance for each of the valves (# intake and # exhaust).
(...Find TDC, Get our your feeler gauges, and write down the clearances)

Assuming your current clearance specs are out of range of any of the intake or exhaust valve clearances, you should proceed to step 3 and determin which shim (pill) is needed. Note: Valve clearence will be reduced ("tigher"/less) as the valve wears. So, loose valve clearance (within factory spec) is a good thing!

3) If you don't already have record of the current shims (pills) that are in each valve, pull them out and measure each valve shims (pill) with a micrometer to get the number.
(Even if you have record, it's a good idea to pull them out and measure them anyway to ensure accuracy.)

4) Plug in all of your specs into this calculator to get the new shim (pill) number/size for each valve.
If all of your measurements have been correct, this calculator will ensure that each valve is now adjusted to proper spec clearances.


Since shims (pills) are usually sold in increments of .5mm, it may not be possible to install the exact shim this calculator states you need. So, choose your size wisely from the availalbe shims sold. And of course, check your valve clearances after each new assembly.

If you are fortunate enough to be able to choose between two available shim sizes (within factory spec), assess how soon you wish to perform this exercise again. If you believe you won't be into the valves again anytime soon, go for the thinner shim, which will make the clearence larger/loose (within factory spec). Again, will allow for more time and valve wear before the next shim change is needed.