valve shims

because of the forums, i'm really learning a lot, and thanks to big fritz, i had some clear valve shim instructions. So about that, i have some questions
.11-.15 .16-.20
Intake Exhaust
1 .15 .152
2 .10 .13
3 .08 .15
4 .15 .15

This what taken the best i could with the feeler gauges i had, available numbers were... .5 .8 .10 .127 .15 .152 .178 i have more larger ones of course, but these were useful considering my numbers

the .13 was from actually stacking the .5 and .8, i don't know how applicable doing that really is.

now i read that exhaust shrinks with wear, so these numbers point that these are pretty old, and all need replacement.

what about intake? do they shrink? get larger?

should i go ahead and order new shims after getting these numbers from standard gauges? or should i get some metric and not trust this?

what is actually changing in size here? the shims? or their seating? because if the shims are changing in size, the chart in the manual is almost useless and the numbers on the shims are useless, i'd need to take a pair of mics to the shims and get a true measurement and then use the chart.

and lastly, where is a good place to order them? it seems ebay is a bit of a ripoff. thanks for any help!

 

answered my own shrink or get larger question, nevermind on that one

 

It's just Fitz, and you're welcome. The only "R" in my last name is in the invisible part.

The shims aren't changing. The valves are pounding themselves into the head.

It's OK to "stack" feeler gauge blades as long as you're sure they're as clean as they can be.

All of your exhausts are tight; you're two-and-two on the intakes.

Metric feelers make it so much easier; the K-D Tools #2274 is widely available. If you're confident with your math, then you can go by those numbers.

Most of us buy our parts from XJ4Ever. Click on the logo/link in the site banner at upper right; PM member chacal; or send an email to "info AT XJ4Ever DOT com" with your info and Len will hook you up. He carries shims for about half of what Yamaha gets.

 

i tell ya you're damn helpful, sorry i know a fritz and the mind works with repetition. . well ok fitz, thanks a million,most of the helpful stuff i find on here usually stems from a post from you. I posted a few days ago asking about a starter clutch and you set me straight then too. my decisions with this bike have led to having the bike completely torn apart ha. gonna refinish it, and i think i might crack that case if i can find some good resources and tips, i mean hell the motor is already up on the workbench.

I do have one last question though.
can i re-use shims? like lets say cyl 1 needs a new shim, and cyl 2 needs a new shim of the same size as cyl1's old shim, can i just pop it over to the other cylinder?

 

I personally don't re-use shims, but pretty much everyone else does. Go for it.

 

roger anddd wilco, thankya sir

 

Groundswell, there's a couple of us that have a shim pool where basically you trade in un-needed shim sizes for the sizes that you do need. I have one pool, Brad Bowen has another. If you send me a PM, I'll explain it further..........

Dave Fox

 

Heya,

re: "The shims aren't changing. The valves are pounding themselves into the head."

This sounds to me as though the length between the valve surface and the shim surface is decreasing.

My brain tell me that the shims therefore need to get thicker shiums in order to compensate. to push the valves out.

but it looks instead as though the distance between the shim surface and the cam lobe is shrinking and therefore we need thinner shims to compensate. this theory is supported by the shim replacement chart, but then I cant figure out what the hell is happening at the valve end.

Is the valve being ground away to nothing over time?
does this mean that they slowly allow less and less fuel/exhaust through?

 

also, I'm sure I read that its best (for power) to pick the smaller end of the allowable tolerance for the intake shims and the larger end of the scale for exhasut..
or the other way around, I can't find it.

 

Is the valve being ground away to nothing over time?

Yes.

 

Hey Bleedingoxide, As the valves wear they move further into the cylinder head, so the tip of the valve is getting closer to the camshaft. So you need to put in smaller shims to keep the clearance within spec.

 

I'll make it real easy for you: there's no "choice" when changing shims. You don't get to pick-- they're either in spec or they're not.

Because of the ranges and the fact that shims come in .05mm size increments, there is only one size shim that will put any particular valve in spec. Let's take that intake valve at .08mm. One size smaller shim will put it at .13mm, in spec. Two sizes would make it too wide and out of spec at .18; going thicker would decrease it to .03 which is obviously not a good idea.

Generally speaking, most times you'll only need to change one size down (increasing the clearance by .05mm.) Only the really tight ones will need to change two sizes.

It's OK to "stack" feeler blades as long as they are absolutely clean.

 

As Fitz said - you don't have a choice. But if you did,
You would want to be on the tight end of spec for maximum horsepower.
you would have the slightest extra bit of lift and duration.

If you set all 8 to the loose end of spec, the #1 advantage would be maximum time 'till the next adjustment.
The engine would TEND to idle smoother, start easier, and give better MPG, but the effect would be VERY slight. (due to less lift/duration).

 

Trust him on this one. As a test I measured my valves with "stacked" twice, once while wiping them clean between valves and once while not. The latter changed my measurements significantly when I got to the 4th, 5th, etc.

 

I was taught to never stack more than two or three. Despite feeler blades being highly precise, there is a percentage error in each one (due to natural variaces in manufacturing). Once you start stacking a few together you're throwing accuracy out the window (of course that all will depend on what you're measuring, and how accurate you need to be).

 

Good point; I should have clarified. You shouldn't need to stack more than two blades if you have a decent feeler set. You do not want to be stacking even three and certainly not four, and it shouldn't be necessary.

If it is, then you need a different feeler set; I recommend the K-D Tools pn 2274 which is widely available and generally for under $10.

If you take good care of your tools and keep things like your feeler sets "well-oiled" (I wipe every tool down with a shop towel soaked in a light/penetrating oil before putting it away, every time) so there's no sign of rust and the blades are nice and clean it's not a problem.

But you cannot stack bent, nicked, rusty or grimy feeler blades; and you need to wipe off any excess oil; they'll stick together fine.

 

A scout leader told me at a very young age when I was the troop quartermaster (oversee & keep track of equipment used for any scout functions) "You take care of your equipment, and your equipment will take care of you." Its a lifelong attribute I've tried to live by since then.

 

I've been collecting tools for close to 50 years and still have every one of them, and in like-new condition. Quality tools will indeed last a lifetime if you take proper care of them.

*Remember to always "park" your torque wrenches.*

 

Good tools should last for many generations. I'm actually proud to own and use some of my father's tools. He's still alive but not kicking hard, he doesn't walk outside anymore.

He took good care of his tools.

 

I have a lot of my grandfathers tools... They don't make them like they use to!!