Valve adjustment - more lessons learned

[ballisticexchris]

I don’t see it as paranoia. I figure most of the folks like myself are just doing their due diligence on properly maintaining their machines.

At least that was what I was taught.......

 

[WJBertrand]

Yes, a slight drag. Not a force fit is how I was taught. However, I'm sure the engineers allow some tolerance for the difference in feel.

Agree, Forcing a feeler gauge in can actually push the valve partly open, giving you a false reading. Don’t do it.


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[Tenman]

I hate to chime in on threads like these because they always turn into "well, I was taught...", but against my better judgement, I just can't help myself sometimes. LOL
From 1973 until 1981 I was a Kawasaki and Suzuki mechanic. From 1983 until 1989 I worked solely for Suzuki. In those years I went to all the OEM seminars these manufacturers had from the Z-1 (1973) to the GSXR 1100. In that time period, the three "main" types of OHC valve opening systems that we have currently (rocker arm, shim over bucket, and shim under bucket) were all in use in various engine configurations. I quoted "main" because I have no experience with pneumatic and desmodromic systems. For the last thirty years, I have mostly fiddled with my own herd, and friends bikes, and for a couple of years, a roadrace team.

This is what WE were taught by the companies that actually build these things...
Rocker arm operated valves...
1)Need clearance attention the most.
2)Have specific settings (not a range).
3)Generally gain clearance over time.
4)Are checked / adjusted by inserting the correct feeler gauge for the specific clearance. If the gauge goes in with no effort, or will not go in at all, the valve should be adjusted to spec. To accomplish this, the adjuster screw on the rocker arm should press the feeler gauge against the valve stem in such a way that AFTER the locknut is tightened, there is enough resistance in the feeler gauge to feel snugness moving it back and forth.

It is generally accepted that the wear between the cam lobe and rocker interface and the rocker arm adjustment screw and valve stem, are greater than the wear of the valve face and seat, thus the clearance increasing.

ALL SHIMMED valve clearances are a "setting" range, NOT an "operating" range. I think some people need to let that sink in. What that means is the engine manufacturer is saying that you can set a shimmed valve at the MINIMUM of the clearance range, (or MAXIMUM for that matter) given in their specs., and you are in no danger of engine damage from a valve getting too tight or too loose for the duration of the valve adjustment interval.
In shim OVER bucket systems the clearance range is narrower and tighter, and the clearance check intervals are more frequent than shim UNDER bucket systems. The reason for that is two fold. In shim over bucket valve trains, the clearances tend to increase between intervals, about 80 percent of the time, and with too much clearance the chance of spitting a shim is greatly increased. Also, may engines with shim over bucket valve trains did not have rev limiters which was another cause of spitting shims. It is generally accepted that the wear between the cam lobe and the shim is slightly greater than the valve face and seat which lead to clearances increasing. However, engines that were revved to the point of occasional valve float, would see their valve clearance decrease over time because of the hammering the valve face took, if they didn't spit a shim first. LOL

Which brings us to the most dependable and durable of the OHC systems, the shim UNDER bucket. Nowadays, with captured shims, rev limiters, and water cooling commonplace, valve clearances can be far greater than ever. This is the main reason for extended valve check intervals.
More likely than not, when a shim measures .001" less than the minimum setting at valve check time, that valve was probably at the minimum clearance range out of the factory. From my experience, I would bet that if left alone until the next clearance check, it would still have the same reading. None of these engines are in any danger of valve damage unless their clearance reaches zero, and I've yet to see that happen in a shim under bucket system, some in excess of 150,000 miles with no adjustment, ever! I'm in no way advocating a no maintenance approach to your beloved steed, but I think there is WAY too much hysteria when it comes to a valve that is .001" too tight.

Furthermore, a valve adjustment interval is arbitrary at best. No one knows how someone is going to operate their motorcycle. What a valve adjustment interval is based on, is the amount of estimated revolutions an engine is going to turn before the manufacturer says the valves need checking. The same manufacturer that wants you to change your plugs at 12,000 miles, your hoses every four years and a whole host of other things that most owners scoff at and think is way too soon. Let's create an extreme case scenario. Rider#1 likes to do all riding in first gear only. Rider #2 loves to get into sixth gear as soon as possible and do all riding in sixth gear. They now both have 24,000 miles on their bikes but rider#1's bike has turned DOUBLE the engine revolutions in the same mileage. Go figure.
So what's the paranoia about valves? If, and that's a big if, they are getting too tight, you will have a ton of warning with the bike becoming hard to start and running crappy, before any burnt valves are in the picture.

That was very interesting

 

[Nikolajsen]

Interesting...
I'm an old guy, so I knew all about the rocket arm valves.
But the shimmed....not so much.
Thank you

 

[bnschroder]

Do people generally replace the clutch cover and cylinder head cover gasket when they check the valves or only when they muck them up?
And do you really need to drain the oil to remove the clutch cover? The manual doesn't seem to indicate that.

 

[RCinNC]

Scott, that was a great post, and a great explanation. Thanks for contributing your experience!

 

[jrusell]

Do people generally replace the clutch cover and cylinder head cover gasket when they check the valves or only when they muck them up?
And do you really need to drain the oil to remove the clutch cover? The manual doesn't seem to indicate that.

You do not need to drain the oil. Look at your oil level sight glass. That is where it will be, about 2 inches lower than the clutch cover.
I just had my clutch cover off. The gasket came off in one piece and could have been reused, but I had one on hand so I put a new one on anyway. If it doesn't tear a light smear of rtv on one side and reuse should not be an issue.

I haven't had the valve cover off the Tenere yet, but on other bikes I have never had an issue reusing a rubber valve cover gasket when doing a valve check.

 

[SkunkWorks]

The last three bikes I have owned, were ALL shim-over-bucket.............all Yamahas.
XJ600 Seca-II, FJ1100, and FJ1200.
Every single time I have checked/adjusted the valve clearances, they ALWAYS tighten up...........meaning the valve face and seat wear, the shims do not.
I'm not sure exactly what kind of steel those shims are made of, or what kind of hardening process is used, but they are certainly a lot harder material than the valves are made of.
I always measure the shims with a micrometer when I pull them out...................I have measured shims that have been in the engine for many-many miles, (50-80 Thousand miles) and there is virtually NO wear on them whatsoever................This has always boggled my mind.

 

[Checkswrecks]

The shims are hardened and take their load over their entire surface area, so there's not a point load they are dealing with.

The valves are hardened but not as hard and the metallurgy is different. The reason they and the seats wear is because they erode in the path of the burning exhaust gasses.

Silicone gaskets like at the rocker cover can generally be re-used if not damaged during removal. Paper (or similar) gaskets need to be replaced.

 

[MattR]

Thanks for that post Scott. Very interesting


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[bnschroder]

I would love for someone to check their valve clearance on their factory-new S10 and then after 26k and tell us all the result. I remember seeing posts saying "out of spec the first check, but then stayed fine for the second one", and I wonder if that is due to "seating" of the valve, or because the factory just put them in on the tight side but they didn't budge in the first 26k either.

 

[Fireplaces]

I don’t see it as paranoia. I figure most of the folks like myself are just doing their due diligence on properly maintaining their machines.

At least that was what I was taught.......

I hate to chime in on threads like these because they always turn into "well, I was taught...", but against my better judgement, I just can't help myself sometimes. LOL
From 1973 until 1981 I was a Kawasaki and Suzuki mechanic. From 1983 until 1989 I worked solely for Suzuki. In those years I went to all the OEM seminars these manufacturers had from the Z-1 (1973) to the GSXR 1100. In that time period, the three "main" types of OHC valve opening systems that we have currently (rocker arm, shim over bucket, and shim under bucket) were all in use in various engine configurations. I quoted "main" because I have no experience with pneumatic and desmodromic systems. For the last thirty years, I have mostly fiddled with my own herd, and friends bikes, and for a couple of years, a roadrace team.

This is what WE were taught by the companies that actually build these things...
Rocker arm operated valves...
1)Need clearance attention the most.
2)Have specific settings (not a range).
3)Generally gain clearance over time.
4)Are checked / adjusted by inserting the correct feeler gauge for the specific clearance. If the gauge goes in with no effort, or will not go in at all, the valve should be adjusted to spec. To accomplish this, the adjuster screw on the rocker arm should press the feeler gauge against the valve stem in such a way that AFTER the locknut is tightened, there is enough resistance in the feeler gauge to feel snugness moving it back and forth.

It is generally accepted that the wear between the cam lobe and rocker interface and the rocker arm adjustment screw and valve stem, are greater than the wear of the valve face and seat, thus the clearance increasing.

ALL SHIMMED valve clearances are a "setting" range, NOT an "operating" range. I think some people need to let that sink in. What that means is the engine manufacturer is saying that you can set a shimmed valve at the MINIMUM of the clearance range, (or MAXIMUM for that matter) given in their specs., and you are in no danger of engine damage from a valve getting too tight or too loose for the duration of the valve adjustment interval.
In shim OVER bucket systems the clearance range is narrower and tighter, and the clearance check intervals are more frequent than shim UNDER bucket systems. The reason for that is two fold. In shim over bucket valve trains, the clearances tend to increase between intervals, about 80 percent of the time, and with too much clearance the chance of spitting a shim is greatly increased. Also, may engines with shim over bucket valve trains did not have rev limiters which was another cause of spitting shims. It is generally accepted that the wear between the cam lobe and the shim is slightly greater than the valve face and seat which lead to clearances increasing. However, engines that were revved to the point of occasional valve float, would see their valve clearance decrease over time because of the hammering the valve face took, if they didn't spit a shim first. LOL

Which brings us to the most dependable and durable of the OHC systems, the shim UNDER bucket. Nowadays, with captured shims, rev limiters, and water cooling commonplace, valve clearances can be far greater than ever. This is the main reason for extended valve check intervals.
More likely than not, when a shim measures .001" less than the minimum setting at valve check time, that valve was probably at the minimum clearance range out of the factory. From my experience, I would bet that if left alone until the next clearance check, it would still have the same reading. None of these engines are in any danger of valve damage unless their clearance reaches zero, and I've yet to see that happen in a shim under bucket system, some in excess of 150,000 miles with no adjustment, ever! I'm in no way advocating a no maintenance approach to your beloved steed, but I think there is WAY too much hysteria when it comes to a valve that is .001" tighter than the original minimum.

Furthermore, a valve adjustment interval is arbitrary at best. No one knows how someone is going to operate their motorcycle. What a valve adjustment interval is based on, is the amount of estimated revolutions an engine is going to turn before the manufacturer says the valves need checking. The same manufacturer that wants you to change your plugs at 12,000 miles, your hoses every four years and a whole host of other things that most owners scoff at and think is way too soon. Let's create an extreme case scenario. Rider#1 likes to do all riding in first gear only. Rider #2 loves to get into sixth gear as soon as possible and do all riding in sixth gear. They now both have 24,000 miles on their bikes but rider#1's bike has turned DOUBLE the engine revolutions in the same mileage. Go figure.
So what's the paranoia about valves? If, and that's a big if, they are getting too tight, you will have a ton of warning with the bike becoming hard to start and running crappy, before any burnt valves are in the picture.

hreat reading have you ever herd of a Yamaha s-10 or st1300 pan burning cams from not adjusting with no cold start issues.

 

[treybrad]

I'll add my $.02 to the discussion here. There is a TON of great info in this thread and the thetenerist site -- many thanks to all those that have done this job before and posted up their experience.

First off, this was everything it was promised to be -- a major PITA. In fact, I've been apprehensive about this job before I even bought a Tenere. I read about what a pain it was when doing research on the bike and made a mental note... so I've had two years to let this to fester in the back of my mind.

I consider myself a relatively competent mechanic, I've done valve check/adj on multiple bikes and cars over the years and do all my own maintenance, but this really pushed my mechanical aptitude this weekend. Looking back, it's really not that bad (easy to say now) but there are so many little things that can make the job a lot easier, and a lot of little things to overlook that can turn it into a complete disaster.

Things I did wrong...

- Removing the valve cover: I did not remove the brackets holding the hard brake lines in place that run back to the ABS unit, I just completely overlooked that step in the shop manual and in this thread. When reinstalling I undid everything and the valve cover went back on so much easier. If the cover isn't coming out by pulling it straight out (you don't need to twist/rotate it), stop and find what's in your way. It's really not that bad with the wiring on right side zip tied out of the way and those brake lines on the left zip tied out of the way.

- Marking the cams/chain: More marks don't necessarily mean better, at least in my case. I made multiple (and not entirely clear) marks on my exhaust cam and on reassembly didn't notice that I had the wrong marks lined up until after I had torqued everything back down, reset the CCT and tried to turn the motor by hand. I wasted a lot of time having to go back and repeat removal of the CCT, zip-tieing things, removal of cam caps, etc.

Things I did right, mostly thanks to the tips on this site...

- Resetting the CCT with a vice helps a ton, I'm not sure how you'd do it without one. Note that the CCT plunger/piston has to spin in the body of the unit. I was twisting the housing and didn't realize why it wasn't plunging back in until I noticed that the piston was spinning as well. An old inner-tube on the vice fixed that problem.

- Spin the motor by hand once you have it reassembled. Multiple times. My cam installation error would have been absolutely catastrophic had I buttoned everything up and hit the start button.

- If you do have to pull the cams, taking the time to mark the other side of the sprocket with a file or something (you know, the side you can actually see) is a great tip.

- Pressurizing the crank case via the breather to make sure your valve cover gasket is seated correct is a nice tip and piece of mind since you can't see the perimeter of the entire cover very well.

- Mark connectors/hoses/cables. There's a LOT of spaghetti down there once you have everything disconnected... I marked everything that looked like it'd be even remotely confusing later with blue painter's tape and a marker (top throttle cable / green electrical connector / etc).

Other general advice... don't skip it. I'm a relatively tame rider, I don't know that I've ever hit the rev limiter on this bike... almost all of my miles (26k miles) are highway cruising and commuting via backroads. I was not expecting to have to swap shims on this thing with my riding style but every exhaust valve was tight, between .19mm-.21mm (spec is .22-.28mm). The earlier talk about them being set at the tight end of spec from the factory I would bet is right. Now that I have them set out to the loose end of spec I don't expect to ever have to swap another shim (knock on wood). Intake clearances were all fine towards the middle of spec.

So long story long, it's a huge PITA but completely doable job. I probably spent 15 hours on it this weekend but now that I know what I know I think 7-8 hours would be a reasonable estimate. If you don't have to adjust the clearances I'd think 4ish hours to get in there and get back out.



Good luck!

trey

 

[gv550]

I’ll add two cents here too.
I remove the front wheel and forks, this makes access to the valves much easier. Just set a shop stool in front of the bike, nice overhead lighting, and sit there with the engine straight in front of me.
A bit more work but at 26k the forks are due for an oil change anyway and the steering bearings are past due for lube and retorque.

 

[Clawdog60]

It would be nice to have an extra $2500 laying around to pay a shop to do this.

 

[tntmo]

It would be nice to have an extra $2500 laying around to pay a shop to do this.

If the resale keeps dropping on these bikes, I can almost buy another for that price!

 

[ballisticexchris]

It would be nice to have an extra $2500 laying around to pay a shop to do this.

Wow that's a lot of money for a valve adjustment. My local shops charge around 400.00-600.00.

 

[Cycledude]

Wow that's a lot of money for a valve adjustment. My local shops charge around 400.00-600.00.

And that also seems very expensive but it’s a job that needs to be done so there ain’t much choice.

 

[Xclimation]

I don't trust shops that includes dealerships. Only way I'd trust them is with me standing over who is touching my bike. And for the time...I might as well do it myself.

 

[Sierra1]

Y'all are making me appreciate my dealer more and more.