Disclaimer: This is meant as a guide only, please purchase a service manual or take it to the shop if you're unsure of what you're doing. Cross reference helps, so watch the videos I posted under "reference" and another guide written for another bike also under the same section. I take no responsibility for any damages due to breaking, kicking, cursing, or even beating your wife while performing this process.
Finally, if you've come to this link, that means your engine valve clearance is out of specification and it needs to be adjusted. This how-to is a continuation of the adjustment process posted below. This guide is not for checking for valve clearance. Use the link below if it's your first time performing valve clearance.
Camshaft Tensioner Tool (Can be crafted, see below.)
Micrometer or Caliper Measurement Tool
All other standard mechanic tools
Chips, Beers, Soy Sauce, Ketchup, whatever keeps you full. It will take 1-2 days up to couple weeks depending on your knowledge and given you didn't order any replacement parts that you broke like I did.
If you refer to the link above to do your valve clearance measurements, DO NOT install the Cylinder Head Cover or the Timing Cap. Leave it there as you're going to work on the engine.
Line up the index mark T with the notch (figure 35) and make sure the "IN" and the "EX" line sits flush with the engine (figure 36). If you're having trouble lining up all three, just line up the index mark T. This means that the cylinder is at TDC (Top Dead Center - figure 37). The camshaft "IN" and "EX" can be adjusted to sit flush with the engine casing later.
Fabricate the Camshaft Chain Tensioner Tool with a sheet metal thickness of 1.0mm. If you don't have one handy, you'll need to find a small screw driver that fits inside the tensioner and somehow hold it in place. You can also order one at Honda Dealership, part #07ZMG-MCAA400.
Remove the toolbox, camshaft chain tensioner lifter sealing bolt, and the washer. Insert the Camshaft Chain Tensioner Tool into the tensioner and rotate it clockwise until it is fully retracted. It's a flat head bolt inside that you're trying to turn. You'll will feel the friction as the spring compresses and it will want to spin the opposite direction. Once fully retracted, lock the tensioner in position but leave the tensioner component on the engine. Do not remove it yet. Failure to do this might cause damages to the engine.
Locked position pictured below:
Remove the Chain Guide bolts and the Chain Guide.
Last edited by dreamzboy; 08-11-2011 at 01:34 AM.
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Loosen all 20 bolts securing the camshaft in a crisscross pattern slowly and evenly. Do not loosen any one bolt all the way out. You will damage the camshaft holders and other components.
In a nutshell, bolt 1 - 8 are the ones with a copper washer. When removing these bolts, BE EXTRA CAREFUL. If the copper washer falls inside the engine, the magnetic tool will not help. Bolts 9, 10, 13, 15, 17, and 19 are short. Bolts 11, 12, 14, 16, 18, and 20 are long.
Note the label "L" for left and "R" for right on the camshaft holder. It will need to be in the exact position when reinstalling.
Lift both camshaft holders off. It might be hard to lift, but use a mullet or any soft hammer and gently tap on the casing to get it to budge. If you're going to use a flat head to lift, make sure you take proper care as you don't want to scratch the engine surface. Watch for the locating dowels as shown in figure 57 under step 7.
Remove the Right Side Locating Holder labeled as "B" in figure 44.
Use a permanent marker or any pen that will stick through oil and mark the position of the chain to the sprocket. This will save you from doing any guess work when you put everything back. I didn't label mine because it was my first time doing valve adjustment and lacking experience.
Use a rope, rubberband, or bungee cord to secure the chain to the bike's frame preventing it from dropping inside the engine. You'll need a miracle to fish it out if it is dropped inside.
Removing the camshafts are optional. After so many tries, I was able to get the shims out of the valves without removing the camshafts. I derailed the "IN" camshaft to one side while removing the valve lifter and the shims and did the same for the "EX" camshaft. If you can't get access to the shims, then remove the camshaft. Be sure to note which one is "IN" and which one is "EX" and its position.
Use the magnetic tool to lift the valve lifter bucket and the shims from the engine valves. Replace the shim with the correct size and install it back into the engine NOT on the valve lifter bucket. It will not stick!
Important: The valve lifter will need to be in the EXACT location where it was taken out. If you don't want to deal with the valve lifter being shuffled around, I suggest do one valve adjustment at a time and put it back.
*Refer to the excel sheet below for Valve Clearance, Old Shim Thickness, and New Shim Calculations.
Let's say my valve clearance is .002" or 5.08mm out of spec. The measured old shim thickness is .076" or 1.929mm. The new shim calculated by the formula, A = (B - C) + D, yields .080" or 2.035mm. The closest shim that they've manufactured is .0787" or 2.00mm. Inserting a 2.00mm which is labeled 200 will put my valve clearance out of specs. This is where you'll have to use your best judgment and take the average. Old shim's thickness is 1.929mm, new shim thickness suggested 2.00mm, your best bet is to use 1.95mm or 195. The average used here is not the exact average but manufacture only produce a .05 incremented shim, pick the one closer to the original shim thickness.
Once all the shims are replaced, it's time to put back the camshaft, chains, camshaft holders, and etc...
Make sure the cylinder is at TDC. It shouldn't be moved during the the camshaft removal process. Install the labeled "EX" or exhaust camshaft toward the front of the engine. Line up the index mark "EX" with the engine casing and loop the chain around the sprocket. If you've initially marked a reference point as described in Step 8, line it up with the marks.
Instal the intake camshaft the same way as the exhaust camshaft and recheck to make sure the "T" index marked is at TDC. Adjust if necessary.
Install the right side camshaft holder. It is shown in Step 7 above. Push it down as far as you can and check to make sure the camshafts are locked into position. Do not bolt it down yet.
Install the two center camshaft holders in place. Note, they will not sit neatly on top of the cylinder head due to spring pressure.
Applied a bit of engine oil onto the bolts and hand screw all 8 center bolts and washers. Next, hand screw the remaining 12 bolts in the order shown in step 5. In this order, gradually tightened bolts 5, 6, 7, and 8 1/4 to 1/2 turn at a time to push the camshaft holder down evenly. Then, tighten the remaining bolts from 1/4 to 1/2 turn at a time in the correct order. Finally, torque the bolts to 12 Nm or 106 in.-lb. I broke one of the bolt because I over torque it and too cheap to buy a torque wrench. It cost me $8 for a new bolt and 1.5 weeks of waiting.
Slowly and carefully un-tension the tensioner by turning counter-clockwise. It will violently spring back so becareful.
Check for valve clearance again as described in the previous how-to guide. If any of the valves are not within specification, repeat this guide to change out the shim. Failure to do so will cause damage to the engine and it will not start. I had to redo this process at least 5 times, so again, choose the new shims closest to the original shim. Too close will put your valve clearance out of spec again. Make your best judgement.
Install the camshaft chain guide, timing hole cap, and cylinder head cover. Before reinstall the cylinder head cover, remove the old gasket sealant and apply a small amount of new gasket sealer into the cylinder head cover gasket, especially the half circle section. Torque the cylinder head cover bolts to 10 Nm or 88 in.-lb. Again, broke another bolt here. Cost another $8, 5 hours trying to remove the remaining piece, and 1.5 week for new parts. I went out and got a torque wrench immediately. You may get by without a torque wrench but some of these bolts have been under a lot of stress and it's old so it may not have the same strength as when it was new. Bottom line, get a torque wrench. I'm happy with it and all my installation has been worried free.
Check and double check for valve clearance; otherwise, you'll end up wasting a lot more time going back to fix the issue. If everything meet specification, reverse the installation step as described in this guide and the previous guide. Before slapping on all the fairings, make sure the bike does start first.
So you're saying it's not necessary even at 50k miles?
Great write up btw.
It IS necessary. I'm glad I did it after finding out that 14 out of 16 valves on my bike were out of spec. I feel safer and I would like to keep my bike running smoothly that's why I had to adjust it. I recommend you should check at 16/32Kmi per service manual, but I'm just giving you a rough idea of how long you can delay this project and by how much the shims fall out of spec.
For most people, they'll never get to 50Kmi to perform this adjustment. Just to be clear, 50Kmi is not a miracle number. I just happened to be that lazy. Other bike may get away with 60-80Kmi or fall short at 32kmi depending on how they ride, street or track, aggressive or not. If you're planning keep your bike for awhile, it doesn't hurt to adjust it.
Very nice thread....So I measured all my valves after 33k miles - and Only 1 of this is off (1 of the cyc 2 intakes) but only by .001" ....Is it worth changing the shim? Will they have a shim just .001" larger than my current one?
If you're going to replace it mind as well get everything within spec. If it still is, then you don't need to. It's really your call. If mine were to sit at the border line, I would rather have it sit right at the middle of the spec. It will make you happy as well as the bike.
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