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My 2012 Yamaha R6 has about 12000 miles on it. During that times I've had a couple rough accidents and I think the combination of those two factors it may be a good idea to check my valve clearance because I feel like I've lost some power. Is this a good idea or am I more likely just going to discover I've wasted my time and it was unnecessary.

I do the majority of my own maintenance and have a buddy who runs a shop that I can call on for help whenever ai get in over my head.

  • There are other (simpler) things to check for. Exhaust leaks (gasket maybe?), condition of various sensors (air, lambda), intake leaks – Zaid Aug 31 '15 at 8:38
  • Frequently, with these types of motors (under the bucket shim head), the valve clearance will be taken up by the valve face impacting the valve seat over time. if, when the engine is hot, the valve clearance is consumed by expansion of the valve stem when it's hot, the valve will hang open just a bit resulting in power loss. If the issue persists without remediation the valve face can get burnt or the engine can be very hard starting when cold as their would be compression loss due to the valve hanging open a touch. – DucatiKiller Aug 31 '15 at 21:45
  • I don't believe that getting in an accident would change your valve clearance. You have an under the bucket shim valve train with very few components, The adjustment shouldn't change from an accident. Is this still an open issue? – DucatiKiller Dec 8 '15 at 14:10
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According to this User Manual on Page 53 (section 6-3) a Valve Clearance check should be carried out every 26,600 miles (42,000km). It also highlights any other maintenance that should be done and at what intervals.

I think checking is relatively simple (assuming you are handy with a toolkit.

I found a site that gives this method of checking your valve clearances, see if you think its within your skillset

Getting access

  • Remove plastics
  • Drain oil (not required but less messy)
  • Drain radiator (not required but less messy)
  • Remove Seat, tank
  • Remove air box
  • Remove throttlebodies
  • Remove radiator (if drained) or move down out of the way.
  • Disconnect ignition wires leading to your coils
  • Remove ignition coils
  • Use a 5mm allen wrench to remove the value cover bolts and then remove the valve cover.

Checking Valve Clearance

You are now going to need to remove the rather large circle cover on the pickup coil cover.

To check the valves you are going to need a feeler gauge to measure the distance between the cam lobes and the valve bucket. Try to find one that is based on the metric system, in fact we are going to keep everything in metric; because trying to figure out .005in is equal to .127mm is a pain. Also have and sheet of paper out and a pen.

Attach a 12mm socket the bolt that was behind the circle cover. With the ratchet turn clockwise to rotate the cams.

NOTE: Never turn counter clockwise, this direction is against the natural rotation of the engine and can do something really really bad; I don’t know what exactly just don’t do it.

Rotate the cams until the two cam lodes closest to you (cylinder #4) are facing up, and the value is completely closed.

With your feeler gauge check the valve clearance, by trying to cram that piece of metal in-between the cam lobe and the valve bucket.

NOTE: you are measuring the exhaust side currently and the clearance should be 0.21mm ~ 0.30mm so start with a 0.25mm feeler and go from there.

Find the largest feeler that will fit in-between. It is possible to cram a larger feeler then that of the clearance make sure you don’t do this! The feeler should just slide nicely in-between.

Now write down the measurement on you sheet of paper, make sure you write it down corresponding to each value and cylinder.

Rotate the crank again, clockwise! Until you can check the valve clearance for cylinder #3. Repeat the clearance checking procedure then continue to cylinder # 2 and finally #1

Once you’ve finished the exhaust side more over to the intake side and record the clearances there.

  • I think 2012 R6 is Fuel injected. Not sure if the site you mention is for the specified motorcycle, I can see the other instructions are mostly correct, just pointing out. – Shobin P Aug 31 '15 at 13:42
  • @Anarach thanks, updated the text to use throttlebodies rather than carbs. Didnt really read the text as it was on an R6 owners site I assumed it would be correct. – Mauro Aug 31 '15 at 14:41
  • 2
    In order to actually adjust the valves the cams must be removed as this is an under the bucket shim head. The appropriate shim would be inserted to get the correct amount of valve clearance and then cam insertion and reassembly would occur. This is not trivial if the OP has never done it before. – DucatiKiller Aug 31 '15 at 21:42

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