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Checking valve clearance


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I have a 2007 RSV with a little over 41K miles. I just started checking my valve clearance and some of the intake valves are under the recommended levels of 0.11 MM to .015 MM. I have one intake that is 0.004 MM. A few others at 0.08 MM and 0.10. What does this mean when they are under the 0.11 to 0.15 MM? I have two exhaust at .015 mm the rest are with in the 0.16 to 0.20 mm. I'm going to run through checking the clearance again to be sure. I have not pulled the shims out yet to look at the numbers.

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Guest Jamsie

I dont know if yamaha use titanium valves , if they do they are prone to stretching, as the big end hammers against the valve seat it distorts the valve slightly, as opposed to mushrooming the valve stem on cams that use tappets.

once you go to the smallest shim the next step is to replace valves

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The shim type set ups tend to "seat" the valves in the head. Thus the clearance gets less. But most folks I have talked back and forth with seldom find valves on these more than a couple mm out of spec, even with 40k or more. I would indefinably say run back thru and recheck everything. At least once more if not twice just to make sure you get the same numbers. There is a an excel spread sheet here on the site that will help you figure out which shims you need based on what is in it. The shop manual has a good chart in it. Remember the clearances are different between exhaust and intakes.

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Also make sure you are using the correct feelers. That intake that is at "0.004mm", there is no such thing as a feeler that thin. 0.004mm is equal to 0.00015 inch are you sure that you did not use a 0.004 inch feeler for that one? 0.004 inch is .10mm which would make more sense.

 

As mentioned the valve clearance gets tighter as things wear, counterintuitive but that is how it works. If the clearance gets down to zero you will burn up that valve because it does not close and it is while it is in contact with the seat that it can transfer its heat to the head for cooling.

 

Usually, it is the exhaust valves that wear the fastest. When I did mine at 50K there were 2 exhaust valves at 0.001 inch (0.02mm) so they were right on the edge of dying. I set all of my valves to the high side of the range to give the most room for future wear. Depending on the shims you have available, you may have to settle for anywhere in the range.

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Thanks, Flyinfool. My feeler gauges have one side mm and the other inches. I had other intakes at .010 mm, which is just under spec. the .004 one was more than likely a 0.10 mm. I am going to run through checking the clearances a couple more time to be sure I have the correct numbers. I don't have a shim kit so I was going to buy the needed ones. I sure don't want to spend the bucks getting the wrong shims.

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Jeff, I have a bunch of basically non usable shims laying around. Like high 200 to maybe 305 or something. Is there a economical way to grind them down, heat treat and reuse if a fellow knew a machinist fellow? Lucky for me the Victory dont have valve adjustment to worry about. :cool10:

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Your original question "A few others at 0.08 MM and 0.10. What does this mean when they are under the 0.11 to 0.15 MM?" Means that the valves that are too tight will open earlier and close later than they were designed and your compression may well be reduced in that cylinder.

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