Shim Pool?

Did anyone ever setup a shim pool? I need two 220's, a 230 and a 240.
I've got a lot of larger ones to trade.

 

I don't know, but we're going to (I hope at least) have a carb clinic in Michigan shortly (MiCarl--any updates? I hope I didn't miss it or something). I'm hoping we can trade them around or something at that time, and then maybe that could be the beginning of the shim pool. What's kind of a problem is that if we need any, we won't know until the carb clinic, and then it's kinda too late...

 

The XS11 group might have a pool so I'm going to check with them. They shims are the same size.

 

No Pygmy, you didn't miss anything. I still haven't set a date.

ArizonaSteve - I've only got thicker shims. I expect that is a common occurance.

 

I have a bunch of them from 255 to 300 if anybody needs some.

 

Does anyone want to start up a pool here? I'd offer if I had more spare time.

 

i want to know if it will be heated...

with michigans weather as nasty as its been i dont want to go shimming in an unheated pool. my shim trunks arent insulated...

 

I've got a few that I'd throw in (all to big for you steve) Let me know whats involved, and I'd be willing to run the pool

 

In order to have a useful pool it will have to start with a nearly complete set of shims. Even if we got everyone on here to donate all their spare shims it still might not be enough to have the ones everyone might need.

 

I've got a few that I could helppeople out with, but only this side of the Atlantic I'm aftraid.

I haven't had to get any more for years, but when I did they were still available from local shops. Are they unavailble now ?

 

I'm going to check with some of the local shops on Monday to see if any of them still have any of the big, old style shims. One problem is the local shop that used to be a Yamaha dealer back in the day doesn't even carry Yamahas anymore.
It looks like ones from a Kawasaki KZ1000 or KZ1100 will also
fit and oddly enough a Ford Taurus SHO engine (made by Yamaha) also
uses the large 29mm shims so there is more of a choice than just the
Yamaha dealers. Maybe chacal should volunteer to run the shim pool since he already has the full range of shims?

 

I carry all sizes of new shims, both aftermarket and OEM, in stock at all times, and given that you'll only find that two or three need replacing during a typical service, it really is rather inexpensive to do.

With used shims, you take the risk that the indicated size on the shim is still the actual size........although shims are "hardened steel", the hardening process only extend a few microns down into the surface of the shim, and once that hardened surface is breached, the shims wear rather significantly.

Thus each used shim must be miked (measured with an accurate, verified micrometer or other such precision measuring device) to determine it's "real" thickness as opposed to its indicated thickness, or otherwise you risk installing a used shim, thinking it will give you the proper clearance, and finding out (assuming you re-measure the clearances after replacement, as the service manual and common sense dictate!) that the (for example) 270 shim that your original calulations said you needed, and the 270 used shim that you installed, STILL doesn't give you the specified proper clearance............

Now, suppose you just throw the used 270 shim in, and don't bother to re-measure the clearance? Well, it might be right on the money. Or it just might not, in which case you'll STILL be operating with out-of-spec clearances, and even more important, without all of your valves being in spec---and here's the key point which you should ignore only if you wish to have continual, ongoing-forever performance problems--- ALL of your carb work (rebuilding/cleaning/adjustment, synchronization and tuning) is mostly for naught, because you can't "synch" an engine when it is out of adjustment.........and while we're on that subject, let me add that the terminology used is fully incorrect: you don't "synch" carbs, you "synch" the entire engine, one cylinder at a a time, VIA THE ADJUSTMENT OF THE CARB BUTTERFLY VALVE POSITIONING. Understanding that concept is vital to understanding why it is so important to maintain proper valve clearances.

To re-cap:

- you want to be able to have the power output of each cylinder to be equal in order to get the maximum performance, smoothness, and life expectancy from your engine.

- power output of each cylinder is strongly affected by a number of factors, with one of the main user-adjustable features and service parameters being the valve clearances.

- power output from each individual cylinder is measured via the vacuum draw of each cylinder on a mamometer, also known as a vacuum guage. The stronger the vacuum draw, the stronger the power output of that cylinder.

- in order to bring each cylinder's power output into equality---AND HERE"S THE IMPORTANT POINT TO PONDER----you have to DECREASE the power output of the best cylinder(s) to that of the weakest cylinder in order to get all cylinder's power output equal ("equal" meaning in "synch" with each other).

- you reduce a cylinder's output in one of two ways: adjust the valves on a cylinder to not open as much as on other cylinders, or open much more than other cylinders (those two methods are obtained by allowing the valve shim clearances to be out of spec), or you crank the butterfly open or closed on a cylinder's carb. A third method would involve messing sufficiently with the fuel mixtures, via the idle mixture screw, to choke a good cylinder(s) output down to the lowest output cylinder, although that has significant other ramifications of doing so.

In theory and practice, you could actually "synch" an engine simply by adjusting valve clearances on individual cylinders (while leaving the butterfly shaft openings all the same) until each cylinder's vacuum draw, and thus power output, were equal. NOTICE THIS FACT: you could leave all of the throttle butterfly openings THE SAME, and adjust the valve clearances. OR, you can do it the way the factory recommends: FIX the valve shim clearances to proper specifications---in essence, leaving the valve clearance "the same"----and ADJUST the butterfly openings to compensate.

Valve shim clearance checks and adjustments are probably THE most overlooked aspect of maintenance on these engines, mainly because it's thought of being such a pain in the butt to do, and if your clearances are out of spec, you then have to wait for replacement shims to be delivered to you. That's why I carry all sizes in stock, and can normally ship the same day, via priority mail or express mail or whatever service level you desire and wish to pay for.

In reality, CHECKING the clearances isn't technically or mechanically difficult, and changing shims isn't rocket science either, and the biggest hassle with the entire experience is getting the rubber valve gasket back in place during re-assembly---an exercise in frustration without having the proper adhesive. Of course, those owners that use a paper valve cover gasket don't even have to suffer that trial.

Also, when removing the valve cover, you should always check and probably replace the valve cover hold-down bolt washers, as that will go a long way to preventing oil leaks in the valvecover area.

 

Chacal is that a yes?

 

I don't do use shims, I always pitch them. It would be like having a used brake pad pool!

 

I'm in agreement with you 100% on measuring Chacal but that is were we separate. I've swapped shims around (of course after measuring them) successfully for years with no ill effects.
Now you make a very good point about the hardness being only a few microns thick. I, not being a metalurgist or machinist, have no working knowledge of metals beyond that they are hard and conduct electricity.
Has there been any reports of used shims causing problems with the old XJOwners shim pool? I haven't heard anything to date. Now I suspect they have been at it a while so if anything untoward had occured, we would have heard about it by now.
Your thoughts?

 

None of my used shims show any wear and they all measure the correct thickness so I don't think it's a problem.

 

Well, I've run across one or two that were 0.0005 out or so. The surfaces didn't show any degradation so I used them again. I am begining to think Chacal has a very valid point because hardening is not going to be very deep given the cost of the shims. I wish we could do some tests. Perhaps I ought to sacrifice one or two shims in the name of science. Is there a way to determine hardness across the cross sectional thickness if I cut the shim in half?

 

Unless people re-measure their clearances after re-installing a used shim, they'll never know whether there is a "problem" or not. I would hazard a guess that many people do NOT re-measure. As far as any problems surfacing, remember: you CAN compensate for uneven valve clearance via butterfly shaft position adjustments during the "synch" process. But also remember: the "synch" process by its nature drags all other cylinders down in output to the level of the lowest (worst) performing cylinder.

It is for that reason that you want all the valves to be adjusted properly, and ideally, each to the same identical setting, even though Yamaha specifies a range of allowable clearances (the absolute number within the allowable range isn't an issue, you would just ideally like to have all the valves at the same setting within that range. Technically, to get the most cam lift (and therefore performance) out of the engine, you would want all the clearance to be set at the same amount AND that amount would be as close as is possible to the low end of the allowable range, meaning as minimal clearance as is possible).

Unless there were other types of problems/issues present, you will never see any surface degredation on a shim. A few microns is way past the ability of the human eye to resolve.

A shim that is off by .0005" is off by .0127mm (I assume that the .0005 measurement is in inches?). Valve shim thicknesses are expressed in millimeters, i.e. a 270 shim is 2.70mm in thickness, and shims come in .05mm increments. So a shim that varies by .0127mm from indicated IS within the range of shim increments, but also notice that it is fully 25% OUT of spec in relation to the incremental size difference (.0127 divided by .05). ALso note that the allowable range of valve shim CLEARANCES is even smaller: .04mm (as in: inlet clearance allowable range is .11mm - .15mm). A .0127mm deviation is almost a 33% deviation within the allowable range.

As far as determining the hardness of a material, there is a Rockwell hardness scale and process/tools for doing such measurements; large testing labs or high-end machine shops probably have such equipment. I would agree with you that a test of the depth of the hardening would reveal that the hardening process applied to the shims is literally "paper thin", if that much!

Look, you can swap used shims around and as long as you re-measure and are sure that the hardened surface treatment has not been breached (which I do NOT know how to check in any cost effective way), then you're fine. On the other hand, new shims are anywhere from $7 to $11 each, you're only going to need a few (hopefully!), and to me, the risk versus savings equation of re-using a worn part---one that is designed, by the way, to wear out and be replaced---just doesn't balance out.

That's why I don't re-use old shims. The factory agrees. Perhaps their engineers were ignorant, or perhaps they were so profit-driven that they were hoping to possibly squeeze an extra $20-30 out of each customer every 5-6,000 miles during the valve clearance adjustment proceess---AND, if you notice the mileage readings of most of these older XJ models, most are in the 15K-45K range AFTER 25 years!! Meaning an average of 1-2,000 miles per year. Meaning valve shim replacement every 4-5 years. Meaning squeezing $20-30 out a customer needlessly every 4-5 years. Meaning an average of $5 - 7 per year. And, meaning---in the "bigger picture" view---schlepping an extra $5 per customer, per year, on top of a, what, $200 service procedure?

Maybe that's what they had in mind. Maybe not. Everyone has to make the decision as to what they think is best given their own specific circumstances, needs, abilities. I'm providing and sharing the most accurate and honest information and analysis that is available to me, and which I consider to be accurate. Trust me, the markup on valve shims is NOT going to make me (or anyone else) wealthy, in any shape, fashion, or manner!

 

>Unless people re-measure their clearances after re-installing a used shim, >they'll never know whether there is a "problem" or not. I would hazard a >guess that many people do NOT re-measure.
Who wouldn't measure the clearances after putting in the new shims to make sure they got it right? I always do. Besides, all the other shims in there are used so I wouldn't want to throw everything off by mixing in some brand new ones.

 

I always re-check clearances after reinstalling shims. Maybe I'm obsessive, maybe thorough, i don't know.

The only wear I've noticed has been where the shim was installed upside down and the numbers have worn off. Correction - on a couple of shims there was a slight discolouration/whitening.

I have, however, checked the thickness of shims with a micrometer (albeit a cheap one). According to my (cheap) micrometer the thicknesses were not exactly as specified, but were the same at all points on the surface - ie no perceptible wear. I did this because some of the shims had no visible number and because I wondered if the hammering would cause any flattening.

At the risk of sounding lazy, I just use a go-no go way of checking clearances. In english: as the inlet clearance is .10-.15mm and exhaust .16-.20mm, if you can put a gauge .10 thick into the inlet gap, but not .15 (or for exhaust .15, but not .20) then it's ok. If the .15 sides easily, but not the .20 (pn the inlet), then one size larger shim is needed.

I check it again because it does seem that not all shim thicknesses are exactly made in .05mm increments - or maybe my gauges are not exact, I don't know. It may be that sometimes a clearance is at the point where it's on the border of sizes, so I have to agonise a bit. Anyway - that's why I check afterwards - to be honest, I thought everyone would - surely you check you've got it right while it's apart ??

The other point is that I obviously have shims from at least two different sources judging by the style of the numbers printed/etched on them - that may be another reason for any variation.

PS - my understanding is that these shims are stamped out of sheet the required thickness. My mind boggles at what could be hard enough to accurately and neatly punch a hole through steel as hard as this.

 

Thorough. You play by the rules. You measure twice and cut once.

Your bike thanks you for your efforts!

Mmmmm....I do not believe that both sides of the shim are hardened.

Mmmmm......that's quite optimistic of you!

I believe that the shims are punched first, ground smooth and sized, and then heat-treated to the appropriate hardness.........

 

You may well be right, I do know that once an engine has settled, there is very little variation in the shims needed unless something else is changed. If I have reground the valves during a top end rebuild, for example there will need to be new shims. What I'm saying is that I haven't noticed perceptible wear on shims (or camshafts, as I'm good on oil changes), despite muc higher mileages than some posters have talked about - 75,000 on the XJ750 and maybe 180,000 on an XJ550 (with engine rplacements and rebuilds over the past 18 years) [That's total mileageincluding previous owners] plus fewer miles on another 550 and 650.

Heat treatment after being stamped out is possible and may mean it's the same thickness throughout (dependant on rate of cooling, heat and metal composition).

 

I was able to get all the shims but one that I needed for the 1100 free from the xs11.com groups free shim exchange program and only had to pay for postage. The last one I got from the local bike shop for $8.00 exchange.

 

By the way, LtDave is hilarious.

But now that the winter FINALLY gave up, I think a regular shim pool would do just fine. My xj is much less cranky too.

But, concerning carb clinics, this can be a problem, since nobody would know what sizes he needed until the day of, and then it's kind of too late (at least if it's supposed to be a 1-weekend thing). Is there any way people could order the most common replacement sizes and maybe send back (or send around) the ones they didn't need? Something like that, anyway.

 

[quote="chacal]On the other hand, new shims are anywhere from $7 to $11 each, you're only going to need a few (hopefully!), and to me, the risk versus savings equation of re-using a worn part---one that is designed, by the way, to wear out and be replaced---just doesn't balance out.

That's why I don't re-use old shims. The factory agrees. [/quote]

So, these are designed to wear out. At what milage did the factory engineers tell us to chunk them all regardless of clearance. If a shim has been in there for 30k miles is it time for it to go? I've read here many places that as time goes on, there is less need for change since the actual wear parts (valve seats) wear less. Are you saying that the shims are the wear part and if so, how often should all of them be changed?

 

The factory said not to...

so I don't re-use old shims period. Maybe it's being overly cautious, I don't frankly know. I DO know that the cost to repair damage caused by a spit shim is many times the cost of a new one; I regularly run my XJs to 8K or 9K... I'm simply not taking any chances.

 

Okay Fitz, this is my last set of questions on this, then I'll stop and let everyone make thier own decision.

1) Where does the factory say not to reuse shims?

2) If the shims being "worn" is an issue, what is the milage limit for a shim? (its not when its out of spec, because that wear is not on the shim, but elsewhere).

3) If I check the clearance and its good, but pop the shim out to read it to make a shim map for future reference and put it back in(or just to find out what I need to fix an out of spec one) how is that different from moving it from one valve to another in the same engine? In other words, once a shim is out of a bucket should it be replaced and if not, why does it matter where I put it back? (yes, I know it chages the clearance on that valve, but other than that. Why is it more likely to be thrown by a different valve than it came out of?)

4) If wear on the shim were an issue to the engineers at Yamaha, wouldn't they have a replacement interval for all shims as opposed to only those whose valves have set enough to be out of spec?

I know its my bike to do with what I want and same for you and everyone else out there.

 

They say to replace shims with "new" pads, i.e. "Install the new pad with the number down." The word "new" can be interpreted either as "new", meaning just that (brand new) or it can be interpreted as meaning "another pad of the same size; "new" as meaning "different from what was originally int here").

In almost all other cases, the word "new" in the service manuals refers to a new part, not a replacement used part.

The wear could be on the shim, the cam lobe, the valve seat, or a combination of all three. Some service manuals specifically states to measure any used shims with a micrometer to verify that the stamped size is the actual size due to wear; otherwise, your calculations will be off.

Shims develop wear patterns in conjunction with their specific cam lobes.

There are no replacement intervals given for many wear items; i.e. brake pads, engine bearings, etc. Why would they specify replacement intervals (miles or time) for items that may not be out of specification?

 

While you are hot on the subect, Len, when I re-shimmed this 900 so I could get reliable comp' readings, the new shims all gave a tighter readings than they should? do they have to bed in? '2' when i put this motor back together I will be reusing the original shims to get me started,no? none will be ok as the valves have been lapped ect, so I check them all & buy 8 new, now will these have to be bedded in & replaced again, or is there a fomula whereby you make some allowance?

 

Hey Wiz, well, I'm not sure that I understand the question(s)? You re-shimmed the engine in order to take compression readings (loosen up the clearances, correct?) but you state that the new shims all gace tighter readings "than they should"? I guess I'm not sure what you mean when you say "should"...................."should" as compared to what other readings?

As far as when you get the valve seats ground, yes that will of course change clearances, you will re-measure clearances and calculate what is needed and then order the appropriate sized new shims as needed.

Obviously, with a "fresh" motor, you can expect some level of clearance changes to occur as the parts all bed in and experience initial wear, etc. since the valve clearances tend to shrink over time as "wear" (or "bedding in") occurs, then it would probably be wise to begin with using the largest possible clearances possible, in other words, if there are any "borderline" clearances to the tight side, go up one valve shim size even if that means going slightly out-of-spec on the LOOSE side, as that "looseness" will go away fairly rapidly, and thus you may not need to exchange shims.

Yamaha recommends that an intial valve clearance check be performed during new engine break-in after 3K miles (5K km) and then after every 5K miles after that, although I would tend to suspect that the majority of the new/fresh engine bedding in of parts occurs much more quickly than that.

 

Don't the shims rotate around the bucket continuously? wouldn't that tend to reduce/eliminate any such wear patters? It would seem to be wise to move to another cylinder at each check in order to reduce wear patterns.

Brake usage varies greatly according to type of driving, who is driving, how fast one drives and how hard one tends to break Hard to predict how quickly brakes will wear. On my Ford Escort some years ago, at 85,000 miles or so, the brakes did not show significant wear as most of my driving was freeway and I try very hard to coast to stops rather than using the brakes. I would also the engine/clutch to do a lot of braking.

Shims, on the other hand, suffer the same use/force each time the engine revolves. It would seem that such wear would be fairly predictable on the average.

 

this same debate is running in two threads; my answer from the other one applies here as well:

There is no "finite life" published for shims as far as I know.

The factory service manual says to use NEW shims when replacing them.

That's what I do. Blind faith persuaded by the argument of $7.50 versus potentially hundreds of dollars.

I do know that each shim develops wear corresponding to its cam lobe. I know the shims rotate during operation and they DO wear, and on both sides.

I replace shims with new ones because the factory said to and I have NO compelling reason to do otherwise. The factory didn't say to use worn shims from other valves in the same engine if they measure ok, they said to use new ones.

For me, it's false economy to do otherwise. Not as bad as gluing delaminated brake shoes back on yourself, but close.

Others may have a different opinion.

 

Local Yama dealership's service department does NOT charge for shims when they do a Valve adjust they just swap shims.. as these are used in a wide Yama model range and are essentially wear proof. They charge for Labour though.
Your choice: Skin your knuckles and buy shims or Pay labour and save your fingers from damage.

 

Gotta agree with bigfitz.....why go to all that trouble to use old parts?I only use new stuff too,especially if its cheap....

 

Disagree. Strongly. And although I don't have the actual facts to prove it, I'll bet you that the cam lobe to shim interface is one of the highest pressure points in terms of contact forces in the entire engine..........amazing that little $ 7.00 discs of metal can be essentially wear-proof. Wonder why they didn't use the same material/process/etc. on other parts?

 

Thanks for that, Len, so err on the slack side.
This is a specific example of the part you were unsure of.
A gap measured .006 with a 255 shim fitted, so I replaced it with a 250, should give me .011, but it only read .008, this was pretty much the story across the board?

 

Wizard, these are metric or fractional measurements (the .006 and .011)?

.006" = .1524mm
.008" = .2032mm
.011" = .2794mm

Shims are in .50mm increments, so going from a 2.55mm to a 2.50mm shim will INCREASE the clearance by .50mm..........thus going from a .1524mm to a .2024mm (which is really close to .2032mm) as it should......


The shim chart specs in the manuals are in mm's.........so when they say an exhaust valve clearance is supposed to be .016 - .020, they are referring to a millimeter measurement.

 

Hi Len, scroll down Here to see my table of calculations, then sit down before you crack a rib laughing. They were all in spec to start with.
Mind you the figures were checked by Big Fitz.

 

Thanks-- I think...

My input here was going to be that this proves Len's point. Your "250" you fitted-- was it NEW? No? Did it mic out to be 2.50mm? Betcha it didn't. If you installed a NEW '250' I'll bet you would have been a lot closer to .011.

Shims don't "bed in" but VALVES do. (Shims wear.) Did you do anything in the interim that would have helped the valves to seat better?

 

In the automotive realm, you can put new hydraulic lifters on an old cam, but you can NOT put a new cam on old hydraulic lifters. And you can't mix up the used ones.

The cam lobe is not ground perfectly square, but at a very slight tip, to induce the spin of the lifter and pushrod. The XJ cam may have the same feature, to induce spin in the shim/bucket.

When the hardness is worn thru, the color of the metal changes. It's more than a few microns. I have seen it in the car and truck parts. To re-iterate Robert's question, has anyone had a failure after re-using a shim?

 

What was funny, Fitz, was that I checked the gaps in thou & did all the calcs in mm, i.e. where I measured .006 thou shoud have converted to mm = 0.15 which is spot on spec (on the large end)
The sad part is I did buy all new shims.
Have a nice day youall.

 

Another argument for a METRIC feeler gauge. Mine doesn't even have imperial equivalents on it.

Nothing wrong with "spot-on" to the loose side, they're only going to tighten up.

 

Been out looking for metric only, not to be had, I will start wearing my glasses more. 8)

 

One wonders if you are legally blind and needing coke bottle glasses.
<evil grin>

http://cgi.ebay.com/ebaymotors/Yamaha-1 ... ccessories

Search google for "metric feeler gauge"

 

biff; he's in Australia. The cost of shipping is prohibitive.

 

I don’t want to get smacked again but this is what I measured used shims at
Shim inches measured
290 11417 11425
280 11024 1100
280 11024 11025
285 11220 1125
285 11220 1120
275 10827 1085
275 10827 10875
270 10630 1065
none had any difference from center to edge

 

Really? I purchased a couple of things from Australia and the postage wasn't excessive.

Okay, okay, baby, stop your crying. <chuckle>

http://shop.ebay.com.au/?_from=R40&_trk ... Categories