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Newbie Valve Adjustment Advice

6K views 24 replies 8 participants last post by  Bainridge_KLR 
#1 ·
Hey Gang,

2016 Gen 2 that just rolled over 20k miles. Pulled her apart to check the valve tolerances and good news, all are in spec. Not as good news, right side exhaust is right at the low end of the tolerance.

My measurements:
IL: ~0.14 mm IR: ~0.14 mm (Tolerance Range 0.1 - 0.2 mm)
XL:
~0.178 mm XR: ~0.16 mm (Tolerance Range 0.15 - 0.25 mm)

So by the book, I'm within spec and have had a few friends say "you're good for now, button her up" but given the time / effort to get everything off to measure the valves, was hoping for a bit more feedback before I bolt it all back up.

Is it worth changing out the shim on the XR lobe to get it towards the looser end of the range or am I over-thinking it ?

Thanks in advance,

Ty
 
#2 ·
If I were being paid to work on Your Bike or I was working on MY Bike, I would install the next thinner shim into each and every one of them. Always adjust to the upper half of specs, when you can. They will only get snugger with mileage.

I see you listed the LH EX valve as 0.178mm so .007inches. So 1 shim size gives .009inches.
I PREFER to only use the inch measures for valve tappets, better for accuracy, IME.
Because I've never been able to find a Metric Feeler gauge in my area with 0.025mm (.001inch) increments.

I like to feel at least a little 'traction' on the thickest spec gauge or I will move back to the next thicker shim to be .001 - .002inch below max specs.
I list my measured clearances like >.006 / <.007 / .007 / >.007 depending on the amount of 'traction' or lack thereof.

Your RH EX valve is Not Below specs, so you should Only go 1 shim size. The other 3 can also go 1 shim size.

If you remove the center cap & spring of the chain tensioner Before you even loosen the bolts on the steel bridge (that inner bolt is Very Short, be careful not to drop it) you Will Not even have to remove the entire cam chain tensioner.
 
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#14 ·
If you remove the center cap & spring of the chain tensioner Before you even loosen the bolts on the steel bridge (that inner bolt is Very Short, be careful not to drop it) you Will Not even have to remove the entire cam chain tensioner.
Paul, I have read this advice from you before. I trust your advice, but in this case I struggled to understand the logic of your advice.

The thingy on the tensioner assembly is like a ratchet, so it can be pushed forward, increasing chain tension, but not back, so the chain tension would remain the same if only the center cap and spring were removed.. If you the tensioner body was removed, there would be extra chain slack available.

When I did my valve clearances, I took the cam chain off the cam sprockets, I feel like I would need that extra slack to get the chain back on the sprockets. So, would you say that if you want to leave the cam chain tensioner assembly body on the bike, then you should leave the cam chain on the sprockets, (As you have advised in other posts) just push them aside to get to the shims?

Thanks Paul

Kind Regards

Matthew
 
#3 · (Edited)
You're not overthinking it. If you're not riding the bike for a few days, it's easier to do the adjustment now, than to take off the seat, gas tank, etc. again to do it later. However, after doing it a few times, you get to where you can do it in 20 minutes or so. ;)

If the exhaust valve is at its lower spec limit, then it needs to be adjusted. You do NOT want to go below the spec, or you can burn the valves. So, "while you're in there" adjust ALL the valves to the maximum clearance.

Go down one shim size on the intakes to get as close to .2mm as you can. opening the intake clearance also will help it start easier.

Go down one shim size on the XL valve, and two shim sizes on the XR valve. If your measurements are accurate, this will put you just a smidgen over .25mm on the XR, but the exhaust valves wear more quickly than the intakes, so in 1000 miles or so, the XR valve will be at .25mm. On valve adjustments, "Loose valves are happy valves."

You can also swap the shims between intakes and exhausts, so you might be able to reuse the shims from one valve to another, and save having to buy that shim. Say your intake shims are 260, and your exhausts are 255. You can move the exhaust shims to your intakes and get the additional .05 of clearance. Then you only have to buy shims for the exhausts. Kapisch?

Edit: I see that PDW posted about the same time I did. He recommends going down only one shim size on your right exhaust valve, whereas, I said two. He's done more of these adjustments than I ever will, but I still prefer to stay on the loose side of the spec. Either way will work. Your choice

And I'll echo what he said about using the inch feelers, unless you can find metric feeler gauges that go to .025 increments.
 
#4 ·
"Loose valves are happy valves."
I dislike the "The slappy valves are happy valves" idea.

Because when owners do that, next week they are posting things like, "I think I can hear my KACR ticking. Do you think it might explode?"
And we should respond,
The KACR can not / will not tick at running speeds unless the Cam Bearings are Worn Out (due to lack of oil) and the camshaft is wobbling around inside the valve cover! You may have Created that tick by adjusting the valve tappets Beyond specs.

Even a tiny little bit of 'traction' on the thickest spec feeler gauge tells me that the clearance is NOT Beyond spec. Or I will go back in to install the next thicker shim.
We are not dealing with a whimpy little ignition point spring here.
 
#6 ·
You want the numbers down otherwise the action of the cam will wear them off and then you don’t know what you have.
 
#9 ·
Thanks gents, really appreciate the knowledge and feedback. One quick question that might impact the readings I'm getting / the actions I need to take. My T mark in the sighting window is lined up damn near perfect but the actual arrow's on the cam gears aren't 100% level with the case. I'm worried I may not be perfectly at TDC and then the cam lobes wont be in exactly the right spot to measure the tolerances etc.

What is the fool proof way to know if you are at TDC ?

Ty
 
#10 ·
The arrows will never line up at TDC, and they don't need to. You only need to be in the general neighborhood of TDC to have the heel of the cam in over the shim. And by 'in the general neighborhood' I mean +/-30*. If you can see the T, you're fine. Move on.

Read this:
"In the manufacture of an internal combustion engine, particularly an overhead cam engine, the most difficult parameter to get right is the valve timing.

The valves sit in the top of the head and are driven by a chain that is wrapped around the crankshaft and two cam sprockets. Those sprockets are pinned to the camshafts. Consider that the head sits on top of the cylinder, which sits on top of the engine case. The crankshaft is mounted in the engine case. Every dimension in manufacturing has a tolerance; some in thousandths of an inch and some in tenths of thousandths of an inch, but all have tolerances.

Here are some of the dimensions of the engine that affect valve timing or the ability to correctly set valve timing:
Centerline of the crankshaft bore to the deck of the engine case.
Thickness of the gaskets, their composition, and their compressibility
The height of the cylinder
The height of the cam bore above the bottom of the head
The spacing between the cam bores
The length of a given number of links in the cam chain
The position of the pin in the camshaft
The position of the slot that the pin fits into in the cam sprocket
The position of the gear on the crankshaft
The position of the groove for the key on the crankshaft
The position of the groove for the key in the rotor
The position of the TDC mark on the rotor

If you look at the arrows on the cam sprockets of a KLR they are supposed to line up, horizontally, with the top of the head. Because of the tolerance stacking in all of the above dimensions, they seldom get it perfect. Make that never. Crap, it's a wonder they can even get it in the ballpark.The position will vary from engine to engine quite a bit. It’s a case of ‘close gets it done’. It is what it is."


Source:Post Page
 
#17 ·
Ok - so new shims arrived, are installed and I've buttoned her back up according to torque specs. I measured and double checked the new valve clearances, all are in spec and near upper end of the range. When I flashed her back up for the first time, I think I'm detecting a valve tap / noise ............

KLR 650 Valve Noise post new shims - YouTube

Before I put some run time on the engine - would love the input of the group. If it is a valve noise, what could be causing it ? I was totally anal about the engine being at TDC, the cam marks lining up perfectly with the engine case etc. Did a fresh oil / filter change before the valve adjustment and oil level is good......no tapping / valve noise prior to valve check / shim adjustment.

Ugh ....
 
#18 ·
Ok - so new shims arrived, are installed and I've buttoned her back up according to torque specs. I measured and double checked the new valve clearances, all are in spec and near upper end of the range. When I flashed her back up for the first time, I think I'm detecting a valve tap / noise ............

KLR 650 Valve Noise post new shims - YouTube

Before I put some run time on the engine - would love the input of the group. If it is a valve noise, what could be causing it ? I was totally anal about the engine being at TDC, the cam marks lining up perfectly with the engine case etc. Did a fresh oil / filter change before the valve adjustment and oil level is good......no tapping / valve noise prior to valve check / shim adjustment.

Ugh ....
This video seems to capture the sounds better: KLR 650 valve noise after new shims #2 - YouTube
 
#21 ·
Thanks Paul - took her for a spin and the bike actually feels great. My measurements post new shims were IL + IR at ~0.17 mm and XL + XR at ~0.21 mm. Wasn’t thinking this was high enough up the tolerance range to get into “slappy valve” territory but bike feels great and as long as its not damaging anything etc then game on.

One last question - why do valve gaps tighten with mileage ? I thought that as mechanical parts interact over time, friction / wear etc would cause the gap to increase .....what’s the scoop ?
 
#20 · (Edited)
Thankfully your bike doesn't have the whip & snap from the engine balancer chain that this follow-up video from your video posting had.


Ps, note that his clutch cable does Not Pass between the 2 coolant hoses. Make for a tighter fit when turning full Left.
 
#23 ·
XL: ~0.178 mm XR: ~0.16 mm (Tolerance Range 0.15 - 0.25 mm)

Hey guys - here are my calc’s for the new shim sizing, love your feedback before I order the new ones. Thanks in advance !
View attachment 32223

My measurements post new shims were IL + IR at ~0.17 mm and XL + XR at ~0.21 mm.
Some of your locations and measurements don't quite jibe. But also we can't feel your feeler gauge blades traction or lack thereof.

And again I'll suggest to only use feelers marked in .001inch measurements for better accuracy, unless you found a feeler gauge set marked in Exactly .025mm increments.

Ride On, nothing in the videos caused any alarm for my ears.
 
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#24 ·
Ditto what PDW said. Ride on. I’d also recheck the cam chain tensioner and the doohickey adjustment.

Norton850 described how the valve seats wear. He said it causes the “valve to seat lower in the head.” What he meant is that the wear causes the valve to seat “deeper” in the head, which makes it move closer to the cam, which reduces the gaps. He’s technically correct, but the word “lower” might have been confusing.
 
#25 ·
Thanks guys - appreciate all the feedback and guidance. This was my first decent size job on the old warthog and it had its moments for sure. I did end up buying a better feeler guage but it still didn't have the tight increments needed to get exact clearance measurements so the numbers aren't totally accurate but we did accomplish the mission to move well up in the tolerance range.

I was actually surprised at the difference in how the big rides - i guess getting the fuel in / exhaust out at the right time is kinda important eh ? :)
 
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