Could we check valves by sound?

GearheadGrrrl

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#1
Just wrapping up my 2nd valve check on the S10, and after 8+ hours wrenching I have again found all valves in spec. Same story with my other bike with a similar engine design, a BMW F800S where after a day's work each time I found all valves in spec at 12k, 24k, 48k, and 72k. So we're spending a lot of time searching for signs of a mostly non existent problem, valve lash loss, while creating a whole bunch of potential new problems like valve cover oil leaks and worse. There has to be a better way...

BMW "airhead" owners are taught that if they can't hear valve clatter, adjust the valves until they do. Railroads are using sensors to monitor locomotive's health so they get sent to the shop when actually needed rather than by a fixed schedule. There are distinct changes in a valves temperature, conductivity, vibration, sound, etc. signatures as it approaches failure. Of those measures, probably the easiest to use is sound, and even our own experienced ears can often note the telltale signs of valve train components going amok. So why not take a database of valve train sounds, then by computer find the distinct sound features of valve trains that are out of spec and headed for failure? Then use that data to build a simple app that can diagnose by sound and predict when valve adjustment is really needed.

Whacha think?
 

WJBertrand

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#2
I think you may be able to diagnose excess valve clearance with sound, but most shim/bucket designs these days tend to wear very little, so clearances close due to valve seat wear. No extra sound is made when clearances close so diagnosing that would be problematic.

I think the real answer is to use hydraulic lash adjusters. The adjuster can be placed in the head so as to avoid it being part of the reciprocating mass. This design should not limit RPMs. The Honda 700 nighthawk S had these and it was a high RPM motor. Such a design would never require any maintenance attention.
 

RCinNC

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#3
I'm not sure how much sound a "too tight" valve would actually make, or if it would even be distinguishable from all the other sounds that are being generated by the "toolbox full of tools bouncing down the stairs" type engine we all love. That's always been one of the drawbacks of the shim under bucket valve design; you can't rely on noise as an indicator that the valve's out of adjustment.
 

tntmo

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#4
Preventative maintenance shouldn't be considered spending time for a non-existent problem. It's a health check, like when you get a physical at the doctor. It's not a waste of time to know that there's nothing wrong with your body, just like it's not a waste to know that your engine is healthy. I did my first valve check early at about 22k miles because I was going on a long trip. Two valves were out of spec. I will be checking them again soon and would be overjoyed to find none needing adjustment. I'm still a bit puzzled about the way people act like this bike is difficult to maintain, it's the same as most any modern bike.
 

RCinNC

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#5
It may be the same as any modern bike, tntmo, but that just means that pretty much all modern bikes (with a couple exceptions) are difficult to maintain, at least as far as the valve check goes. Valve checks are a pain with a shim under bucket design when you have an inline or v-twin engine, and even more of a pain if you actually have to adjust a clearance. I don't think anyone could make a compelling argument that it's a carefree, easy, quick process to do a valve check on a Super Tenere, the way it is with something like a BMW or a Moto Guzzi.

Frankly, it would be great if Gearheadgrrrl's idea turned out to be workable.
 

gv550

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#6
On a single cylinder engine or opposed twin with one intake and one exhaust valve it may be possible to hear individual valve clearance or lack there of, but with a four valve head and with the cylinders paired together I think it would be nearly impossible. Specialized equipment likely exists that could isolate the sound from each valve but not in my garage.
 

tntmo

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#7
It may be the same as any modern bike, tntmo, but that just means that pretty much all modern bikes (with a couple exceptions) are difficult to maintain, at least as far as the valve check goes. Valve checks are a pain with a shim under bucket design when you have an inline or v-twin engine, and even more of a pain if you actually have to adjust a clearance. I don't think anyone could make a compelling argument that it's a carefree, easy, quick process to do a valve check on a Super Tenere, the way it is with something like a BMW or a Moto Guzzi.

Frankly, it would be great if Gearheadgrrrl's idea turned out to be workable.
Well it's the price for progress, I guess you could say. We have a compact, somewhat high revving engine design with less moving parts, the valve adjustment interval is extended considerably but it adds to the maintenance time to adjust them.

Yes, most motorcycle valve adjustments are not easy....single cylinder air cooled bike and BMW excluded. So it's part of the ownership of the vehicle, either ignore the maintenance, pay to get it done or do it yourself. I know a lot of people go with ignore it, this bike seems to be pretty forgivable for that.
 
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#8
Not sure on these new parallel twins. But on my thumpers and my dads old Triumphs, you did not adjust the valves until the motor wont start without adding a little throttle. As soon as you need to give even the slightest bit of throttle to start (when engine is hot), then the valves are out of spec and need adjustment. My Beta started getting a bit hard to start at around 150hrs. I did the adjustment and it's been good ever since. I have over 300hrs on it to date.

On this bike I'm not sure that would work as it's fuel injected. I plan on checking my valves per factory manual on this bike. It looks pretty easy to do on the Super Tenere. Nothing strange.
 

RCinNC

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#9
It's the one maintenance task I contract out to someone else. I figure it's worth it; every two years or so I pay someone the $400 to do it, and since that's the only maintenance task I don't do personally, I figure I'm still ahead on maintenance costs. It's not even so much the checking part, it's the adjusting part that makes me reach for the credit card. I just don't want to get into pulling camshafts, messing up the timing, etc.

I definitely appreciate the 26,000 mile valve check interval, as opposed to the 18,000 mile interval on my V-Strom.
 

Checkswrecks

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#10
Interesting idea and the concept is good, but I don't think it's ready for prime time without a lot of work to develop through testing. We've got 8 valves in a head that is hidden and potentially a lot of chain noise, too.

When these valves go tight the seat gets burned and you are looking at a new head, so I'll keep doing it the old fashioned way.
 

BaldKnob

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#11
I've performed 2 valve checks (2012 Raven) and not needed any adjustment. With my '17, I'll do the 26K check and if in spec will space the interval to 50K miles.
 

EricV

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#12
The idea has merit, but realistically, you need a lot of specific data samples before you would have a reliable bell curve to tell you when to actually take things apart and check them. Think Statistical Process Control. The more data, the better the accuracy.

Personally, with motorcycles and people, there are too many random variables to control. Because of this, I think it would be more challenging to get consistent data that would find the fall off point where the valves needed re-shim.

Add in that rider style makes a big difference in how often Yamaha engines need re-shim. My inline four FJR needed re-shim at the second interval, (52k), then not again until 98k, but the 98k interval had external wear factors that had an unknown impact. (Dusting of the cylinders and valves due to un-metered air flow). I know other owners that are harder on/off throttle that needed valve re-shim at the first interval and second, then things were fine for 2-3 intervals before needing another re-shim.

The '12 Super Ten needed minor re-shim at the second interval, (all exhaust getting tight), and nothing after that, but had a full re-work at 83k due to CCT failure. The '15 has only had one valve check and did not need re-shim, with all valves nicely in the meat of the spec.

From my personal Yamaha ownership experience and my manufacturing experience working with SPC, I suspect additional sensors may be needed before you would get the data you needed to really tell when to re-shim the valves. I think it's possible, I just don't think we'll get there via an independent. I think factory support and static testing under strict controls with sound and temp sensors in various places would be required to gain the necessary number of data points to form real world applicable standards.
 

holligl

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#13
It's the one maintenance task I contract out to someone else. I figure it's worth it; every two years or so I pay someone the $400 to do it, and since that's the only maintenance task I don't do personally, I figure I'm still ahead on maintenance costs. It's not even so much the checking part, it's the adjusting part that makes me reach for the credit card. I just don't want to get into pulling camshafts, messing up the timing, etc.

I definitely appreciate the 26,000 mile valve check interval, as opposed to the 18,000 mile interval on my V-Strom.
Same here, except the dealer mechanic forgot to reinstall the air box breather hose. I found it when I changed plugs and air filter. Check their work the best you can.

Sent from my SM-N950U using Tapatalk
 

bnschroder

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#14
Is there any reliable information what tends to make valves go out of spec faster? I am reading "harder on/off throttle that needed valve re-shim at the first interval and second". Is that it? More wear at higher revs or higher acceleration? I believe someone here once claimed that Longhaul Paul could afford not to check his valves for 160K because that kind of riding was easy on the valves.
And I am also wondering if it's something you could see in the oil? Getting a Blackstone oil analysis is much cheaper than a valve check. Would be great if seeing a certain metric in your oil pass a certain threshold means that you need to re-shim.
 

Checkswrecks

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#15
Is there any reliable information what tends to make valves go out of spec faster? I am reading "harder on/off throttle that needed valve re-shim at the first interval and second". Is that it? More wear at higher revs or higher acceleration? I believe someone here once claimed that Longhaul Paul could afford not to check his valves for 160K because that kind of riding was easy on the valves.
And I am also wondering if it's something you could see in the oil? Getting a Blackstone oil analysis is much cheaper than a valve check. Would be great if seeing a certain metric in your oil pass a certain threshold means that you need to re-shim.
There's plenty of reliable history and info that valve lash change is mostly a function of wear of the seat and a bit from stretching of the valves. The wear can have a number of contributing factors, with the biggest being exhaust gas temperature and rpm's. The EGT alone can have a number of contributing factors which include mixture set by the ECU, rpm, and fuel. Clear as mud and a lot of people make their living off of trying to understand what you asked. As for the on/off throttle part, the ECU has to take input from sensors and then respond, which means that there will be some lean/hot transients through the rpm range.

Paul could have afforded to have his valves checked, so set that part about cost aside. But he also knew/learned that a steady rpm in the middle of the power range meant very few lean/hot transients were happening. His was an odd situation and use of the bike. Plus he knew how conservatively the engine was designed, plus I got the impression talking to him a couple times that once Paul gets an idea in his head you aren't going to change his mind.

Oil analysis won't pick up anything about valve lash till there is a change in the carbon content and by then the valve seats are being scorched.
 

tntmo

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#16
All of this got me thinking about my work in the Navy. I spent the majority of my career in helicopter squadrons as an aviation mechanic. We had vibration analysis programs, usually only done during scheduled maintenance done at certain hour increments (150 flight hours, for example). The vibe gear would read at certain frequencies to see if engines, drive shafts, main/intermediate/tail gearboxes were going out. Pretty interesting, but took a lot of equipment, training and collected results over many years.

Late in my career, the advancement of technology meant that this sort of thing was built into the aircraft. As each crew took the aircraft out for a mission, they brought an empty memory card with them and it downloaded flight data as they flew it. Part of the mission debrief included uploading the data into a computer back at base. It would instantly say if one of the vibe regimes was out of limits and if so we had to down the aircraft and investigate why. It also got sent upline to the manufacturers tech reps who would track trends. Sometimes they would call us and say that even though the aircraft wasn't out of limits there was a vibration regime moving in that direction. Really interesting how often they got it right and found a problem developing.

Needless to say, I don't know if we'll ever get something like this to passenger vehicles or motorcycles, but the technology is out there.
 

markjenn

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#17
A bunch of technology could be thrown at the problem, both to reduce the maintenance burden and to catch failures earlier, but I doubt it would be remotely cost effective. I just wish Yamaha would spend a few bucks making the process easier. For example, after eight years of production, there is really no excuse for camshaft gear timing marks that are on the wrong side of the sprocket to be easily seen while timing the engine.

- Mark
 

EricV

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#18
Oil analysis won't pick up anything about valve lash till there is a change in the carbon content and by then the valve seats are being scorched.
And there in lies part of the problem. At this point, when we see a flag, it's too late. As tntmo suggested, it's possoble, it just takes a lot of data and we are on the wrong end of the data stream.

@markjenn - Interchangable parts. They are on the right side for the other camshaft...

Frustrating, but I get it.
 
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#19
A bunch of technology could be thrown at the problem, both to reduce the maintenance burden and to catch failures earlier, but I doubt it would be remotely cost effective. I just wish Yamaha would spend a few bucks making the process easier. For example, after eight years of production, there is really no excuse for camshaft gear timing marks that are on the wrong side of the sprocket to be easily seen while timing the engine.

- Mark
I don't see anything about timing the engine on this bike. What am I missing here? There is only one timing position on this motor. Pretty simple. Align the K mark of the pickup coil to crankcase mating surface, align intake cam to the cam cap mark, then make sure intake/exhaust cam sprockets marks line up to cylinder head surface. When all three match up then the engine is perfectly timed. If they don't match up then simply rotate crank 360 degrees. The marks do not have to be easily seen. I always use my own colored marker to mark the embedded lines from the factory.

I see nowhere in the service manual where you have the option of using a degree wheel on this engine? Nor do I see anything about timing it? I would think that's opening up a bag of worms on this bike. Pretty common on the thumpers but I'm not sure I would attempt trying to advance/retard cam timing on this bike.
 

tntmo

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#20
I don't see anything about timing the engine on this bike. What am I missing here? There is only one timing position on this motor. Pretty simple. Align the K mark of the pickup coil to crankcase mating surface, align intake cam to the cam cap mark, then make sure intake/exhaust cam sprockets marks line up to cylinder head surface. When all three match up then the engine is perfectly timed. If they don't match up then simply rotate crank 360 degrees. The marks do not have to be easily seen. I always use my own colored marker to mark the embedded lines from the factory.

I see nowhere in the service manual where you have the option of using a degree wheel on this engine? Nor do I see anything about timing it? I would think that's opening up a bag of worms on this bike. Pretty common on the thumpers but I'm not sure I would attempt trying to advance/retard cam timing on this bike.
I believe EricV was talking about setting cam timing when removing the cams to set valve clearance, not adjusting timing.
 
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