Valve Adjustment S10 and BMW

[markjenn]

It may just make the check times a bit less frequent. I don't think it will make a huge difference to the procedure though.

Rotating the heads 90-deg is a huge design change and will likely result in an entirely new and complete different valve train design as either the cams or the cam drive has to be completely re-oriented vs. current design. I wouldn't bet on this new design having much in common with either the old short-pushrod/tappet design or the new (and very odd with each cam actuating both an intake and exhaust valve) DOHC design.

- Mark

 

[GrahamD]

Rotating the heads 90-deg is a huge design change and will likely result in an entirely new and complete different valve train design as either the cams or the cam drive has to be completely re-oriented vs. current design. I wouldn't bet on this new design having much in common with either the old short-pushrod/tappet design or the new (and very odd with each cam actuating both an intake and exhaust valve) DOHC design.

- Mark

Agree, I just assumed it would still be shim under bucket. Take off cover, check clearance, change if rarely required. Same as S10, DL's etc etc etc. Major differences in engines, different level of difficulty to get the covers off, but once you are there, basically the same thing.

The differences are mainly in what you do on the usually rare occasion you have to change one.

With the cylinders still sticking out the sides, it would still be pretty easy to get to, unless they have decided to do a two piece head or something bizarre.

True, or is my ass making noise again.

 

[WRW9751]

The S10 is 24K, but getting to the heads is a fair amount of work and if you need to change a shim, you have to pull and re-time cams which is no picnic and a huge opportunity to do some very expensive damage to your bike if you don't get it right.

I'm no expert and do not have the workshop manual. But in the past Yamaha's shim and bucket adjustments are done with a tool that simply opens the valve by depressing the spring the shim is slipped out (usually with a magnet) and the replacement is inserted. It's a fairly simple procedure after you've reached the valve. The cam stays in place no need to remove it. I can't imagine Yamaha replacing such a simple effective process.

 

[AL-58]

I'm no expert and do not have the workshop manual. But in the past Yamaha's shim and bucket adjustments are done with a tool that simply opens the valve by depressing the spring the shim is slipped out (usually with a magnet) and the replacement is inserted. It's a fairly simple procedure after you've reached the valve. The cam stays in place no need to remove it. I can't imagine Yamaha replacing such a simple effective process.

I've had Yamaha XJ900s, XJ750s, a TDM850 and a TDM900; all had shim adjustment.
The XJs had shim adjustment like you've said with the shim in between the camlobe and the bucket, both TDMs had shim under bucket where the cams have to be removed to remove and change the shims. Under bucket shims are smaller and lighter, supposedly last longer between adjustments. Either method checking the clearance is easy anyway. Can't comment on other Yamaha models just showing that not all Yamahas use the same methods.

Be happy it's not like a BMW K100 16v or K1100, no replacable shims, you have to change the entire bucket (made in different thicknesses)
Al

 

[markjenn]

Agree, I just assumed it would still be shim under bucket. Take off cover, check clearance, change if rarely required. Same as S10, DL's etc etc etc. Major differences in engines, different level of difficulty to get the covers off, but once you are there, basically the same thing.

But the DOHC boxers are NOT "shim under bucket" like the S10, DL's etc. You adjust clearances with different semi-hemispherical ball shims that fit into the camshaft follower. You access these shims by simply removing a circlip on the camshaft follower, removing the follower and swapping the shim. You don't have to disturb the cams or the rest of the valvetrain. I haven't done one, but it looks MUCH easier than shim under buckets. (The shims may be more expensive.)

http://sanjosebmw.smugmug.com/Other/Tech-pictures/10976964_bHf66#767209614_WupU9

Whether BMW can preserve this relatively simple method of shim adjustment in the new water-cooled motors remains to be seen. This DOHC valve train design is HIGHLY unusual in that each cam controls both an intake and an exhaust valve rather than having the typical system where one cam controls the exhaust and the other the intake. One of the most interesting aspects is that valve timing between the intake and exhaust is fixed by the camshaft and can't be varied. I think this is probably a reason why BMW won't push this design further and the new water-cooled boxers will likely have a different/more-conventional design as variable valve timing is going to become more commonplace on motorcycles and this type of design doesn't readily allow it.

- Mark

 

[markjenn]

But in the past Yamaha's shim and bucket adjustments are done with a tool that simply opens the valve by depressing the spring the shim is slipped out (usually with a magnet) and the replacement is inserted. It's a fairly simple procedure after you've reached the valve. The cam stays in place no need to remove it. I can't imagine Yamaha replacing such a simple effective process.

They did. Almost all the new Yamaha's are shim under bucket and as are almost all recent Japanese high-performance DOHC current designs. All, including the S10, require that cams be removed to swap shims. Shim over bucket went out of style in the 90's.

- Mark

 

[Don in Lodi]

The S10 is 24K, but getting to the heads is a fair amount of work and if you need to change a shim, you have to pull and re-time cams which is no picnic and a huge opportunity to do some very expensive damage to your bike if you don't get it right.

I'm no expert and do not have the workshop manual. But in the past Yamaha's shim and bucket adjustments are done with a tool that simply opens the valve by depressing the spring the shim is slipped out (usually with a magnet) and the replacement is inserted. It's a fairly simple procedure after you've reached the valve. The cam stays in place no need to remove it. I can't imagine Yamaha replacing such a simple effective process.

Do we know the Tenere is shim under bucket rather than shim over bucket? My Royal Star with four valves per cylinder is shim over. I know that when higher revs are being obtained that they want the shim under the bucket so it doesn't manage to slip... but anyway, my point being, shim over isn't that tough to do.

 

[markjenn]

Do we know the Tenere is shim under bucket rather than shim over bucket?

Yes we do. It's shim under bucket, pull cams to swap shims. Completely covered in the service manual. We've known since June 2010 when the S10 first appeared. Yamaha's 4-valve head design and valve-gear design for their non-cruiser motors has been more-or-less standardized on a common shim-under-bucket, 24K adj interval, design since 1998 when the R1 appeared.

Higher rev potential is often cited as a reason to go shim-under rather than -over (if you over-rev a shim-over motor, it is possible to "spit" the shim out of the tappet and lunch the engine), but the S10 is so under-stressed and low-revving, I doubt this was any factor in the design decision. Mostly Yamaha does shim-under these days as it is "in style" and because it is associated with the highest-performing motors. It also holds adjustment very well, somewhat better than shim-over, and this is probably why Yamaha's recommended adjustment intervals are relatively long.

Customers just aren't squawking that loudly about the extra service hassles or costs associated with under-shim. They might squawk more if they realized how frequently service people "pencil whip" a valve check with the rationale that they "almost never go out of adjustment". And if the shop flat-rates a valve check - charges the same whether a shim has to be swapped or not - then there is a powerful incentive to judge any valve that is remotely close to spec to be "close enough". I've done perhaps twenty shim-type valve checks in my career on a variety of motors (mostly 4-cyl sportbike motors) and about half have had one or more valves out of spec which indicates to me that the adjustment intervals spec'ed by the mfgs are reasonable and probably should be followed. Not religiously followed but not ignored either. And if you don't do the work, tell the shop you want a record of the measured clearances and what shim came out and went in if any were changed.

- Mark

 

[Don in Lodi]

Cool, thanks.

 

[GrahamD]

1) Thanks for the detail on the BMW Mark. Learned something else. ::008::
2) I agree about the some dealers. Had the same happen to a couple of people I know. Not a big sample, but it makes you wonder. I check mine in the winter teardown, but could have just done my own ..."pencil whip" every time.

So they probably just have a listen and charge.

Cheers
Graham

 

[HoebSTer]

The S10 does use the shim under bucket! Yes the cam will probably need to be removed. I just looked at the manual, seems pretty straight forward.

 

[johnnail]

If BMW would make the R100gs again with the few little things upgraded, they Couldn't make them fast enough

 

[Tremor38]

It's probably easier than a Strom which essentially means disassemble bike until motor is found. (Ok not as bad as some).

If you have a few measurement tools, you can work out what you need and just buy one shim OR you can cheat and buy the next size up and "lap" it to size. A few ways to skin a cat.

But here is the thing. I have never had to replace one. ;D

You rebuild entire motors at home if you want. It's up to you whether you think it is too time consuming or complicated.

The BMW does have the advantage, service wise, of the heads being accessible though. You would think it would cost less.

Yes, even the new overhead cam Beemer boxers with the shims under bucket are pretty easy. You just slide the cam followers off to gain shim access, rather than removing the camshaft.

 

[markjenn]

Here's a good photo of the current DOHC boxer setup. Note that the cams are beveled since the valves are angled with respect to the cam. Must be some pretty sophisticated machining involved in making beveled cams.

The entire head is rotating 90-deg in the new water-cooled motor to put the intake on top and he exhaust on the bottom. Since the crank is going to continue to turn longitudinally in the bike, this means they either have to ditch the chain drive for the cams and turn the the cam drive 90-deg or go to a conventional DOHC arrangement with the cams staying where they are and operating pairs of exhausts and intakes. The latter makes the most sense, but I wouldn't bet on the rocker shims sticking around - I think BMW is likely to "go with the flow" and just do shim-under, especially since the new motor is likely to bump redline up another 500 rpm.

- Mark

 

[RED CAT]

Ok. Have read all through this and still don't know what the actual Valve Adjustment Spec is? As in, what is the measurement? Exhaust/Intake spec? Anybody really know?

 

[S_Palmer]

::015::
Intake .10-.16mm
Exhaust .22-.28mm

 

[RED CAT]

Wow!

S Palmer. Thanks. Someone actually knows. Be awhile before I have to do it as I only have 1 mile on the bike so far. But I do all my own work so like to have all the info. Thanks again.

 

[Rasher]

BMW's do seem easy to do, but this is offset by (at least in the UK) BMW dealer rates typically being 50% (or more) higher than Jap service prices, my franchsied Honda dealer charges £60 per hour, my BMW dealer is £92 per hour, many BMW dealers charge over £100 per hour!

The main worry (Yamaha or BMW) is if they do the more awkward stuff, I have had a ZX9R with a FSH from a main dealer and when I got a friend (and Kawasaki dealer mechanic) to look at it he told me the shimns had never been done (Despite the previous owner paying £500 for a service that included this work)

I changed the FD oil on my GS at 7.5k (supposedly done by dealer 500 miles and again at 3.5k - again with receipts to "prove") and it came out filthy black and sludgy, now perhaps it does get filthy in 4k, but I did it again at 11.5k (I do it with each tyre change) and the oil was pretty clean which suggests the dealer skipped this extra bit of work to up his profit, or the tech guy is on a bonus scheme and skipped it to up his pay packet.

My mechanic friend also told me a story (Late 80's) a Honda dealer mechanic he knew who's boss refused to pay for the special tools to do VFR valve adjustments, when he asked "what happens when you get a VFR in for a valve check", the guy said we just charge him an extra 2 hours labour and tell him they were all OK.

I am not too fussed at "pain in the arse" every 24k, or "piece of cake" every 6k, the real question is does it get done???

Especially with Bucket Under Shim bikes, I am prepared to check screw and locknut systems myself, but with the Tenere I would want it done by a pro, and I do not know of a single main Yamaha dealer in the UK I would trust to do the work, which is why I used my friend, but unfortunately he has since passed away.

For me the biggest benefit is a lot of independant techies are out there that will work on Yamaha's, BMW is a far more closed shop with few independants, the only ones near me are those that have recently lost their BMW franchise - but they still insist on charging BMW rates!

 

[markjenn]

My mechanic friend also told me a story (Late 80's) a Honda dealer mechanic he knew who's boss refused to pay for the special tools to do VFR valve adjustments, when he asked "what happens when you get a VFR in for a valve check", the guy said we just charge him an extra 2 hours labour and tell him they were all OK.

I think this is all too common. As another data point to support that this practice is widespread, reports from owners who do the work themselves often seem to have a valve out of spec that requires re-shimming, but for dealer checks, it is much more rare. I also had the experience where I've attempted to buy a shim from a dealer and found out the the service department doesn't even keep a shim assortment in stock. How often do you think such a shop is going to play it straight and leave a bike disassembled for a week or more waiting on a shim? If the valves are in the same zip code as spec, they'll button it up and get it out the door.

I'm, of course, painting with a broad brush here - there are some truly excellent dealer service departments that do great work. And we're our own worst enemies at times by shopping for price rather than quality of service. I've done tens of shim valve checks/adjustments and I honestly don't see how a dealer can possibly make a buck on most shim-under-bucket bikes only charging $200 or so. It is a good sign if the service department has two different charges depending on whether the valves require re-shimming - this removes the incentive the shop otherwise has to assume things are good.

Valve checks and reshimming is not generally a hard job, but it is a meticulous one, requiring good tools, a clean workshop, good documentation, and good technique. The consequences of a screwup are severe.

- Mark

 

[Tremor38]

I think this is all too common. As another data point to support that this practice is widespread, reports from owners who do the work themselves often seem to have a valve out of spec that requires re-shimming, but for dealer checks, it is much more rare. I also had the experience where I've attempted to buy a shim from a dealer and found out the the service department doesn't even keep a shim assortment in stock. How often do you think such a shop is going to play it straight and leave a bike disassembled for a week or more waiting on a shim? If the valves are in the same zip code as spec, they'll button it up and get it out the door.

I'm, of course, painting with a broad brush here - there are some truly excellent dealer service departments that do great work. And we're our own worst enemies at times by shopping for price rather than quality of service. I've done tens of shim valve checks/adjustments and I honestly don't see how a dealer can possibly make a buck on most shim-under-bucket bikes only charging $200 or so. It is a good sign if the service department has two different charges depending on whether the valves require re-shimming - this removes the incentive the shop otherwise has to assume things are good.

Valve checks and reshimming is not generally a hard job, but it is a meticulous one, requiring good tools, a clean workshop, good documentation, and good technique. The consequences of a screwup are severe.

- Mark

That makes sense. I used to sit right next to my Kawi dealer's mechanic and shoot the breeze with him while he worked. I quickly learned he didn't require monitoring. What you speak of isn't as prevalent at Japanese dealers because they are the king of itemizing every action they take. My Yamaha dealer has a bunch of youngsters working on the bikes, so I check after them a bit more.