Valve adjustment advice

Instead of paying the dealer and not learning anything, I decided to delve into the fun task of adjusting my valve clearance myself for the first time. My 1977 KZ1000-B1 has 17744 miles on it and has never had the valve clearance adjusted. Ever. My dad (the previous owner) is pretty clueless about all things mechanical and never took the bike to a shop for any scheduled maintenance.

I just received my valve-shim removal tool and a good set of metric feeler gauges today from www.z1enterprises.com . All of the valves have basically 0 clearance, in that I cannot insert the smallest 0.04mm feeler between the cam lobe and the shim on any of the valves, after turning the cams to line up with the marks as described in my service manual. I removed each shim one-by-one and took notes on what each one's marked size is. Most of them are 2.70.

The service manual says "if there is no clearance between the shim and cam, select a shim which is several sizes smaller and then remeasure the gap". My question is, since I'm planning to order the new shims from z1enterprises, which sizes should I order? I'd rather not have to take a guess and get it wrong, only to have to ask Jeff if I can exchange for other sizes, deal with shipping back and forth, etc.

Also, do the shims themselves suffer from any measurable wear? I don't have a micrometer in order to check the shim thickness -- is this an issue or can I trust the markings on the shims?

One more question -- some of the shims say "270" and some say "270A". Does the "A" mean anything?

Thanks in advance,
Steve

When you check the valves with a feeler gauge you want to have about .002 to .004 on both intake and
exhaust.Check the clearance on each valve at several
locations of cam position. Check with the cam lobe
pointing preferable straight up or at the 10 o'clock
and two o'clock and see what you get as far as clearance. Just don't go replacing shims unless you
absolutely have to. Those shims are available at
all Kaw dealers for about $10.50 each ranging from
2.0 mm all the way to 3.2 mm. The worst thing you
can do is install a shim that is too thin. Allowing
too much clearance will allow the shim to come out
and if that happens your valve train goes to mush!
Those shims are hardened and although they do
wear they don't wear as much as the rest of the valve train. Suppose you actually don't have any
clearance as you say. If a shim is 2.70 mm then go
to a 2.65 mm , install shim and then measure. A new
valve adjustment will have shims in the 2.25 to 2.30
mm range. The difference beyween say 2.70 and 2.70A
is nothing. Hope this helps.

Have 78 Z1R
78 Z1R TURBO
73 H2 TRIPLE
72 H2 TRIPLE
72 H2 TRIPLE FAST-BY-GAST DRAG BIKE
67 bsa 650 LIGHTING

Had 77 KZ1000
91zx-11
89 zx-10
87 1000r

Vdrumman, a good description by Jess. A couple of minor things that I disagree with, in regards to the explanation of a difficult subject matter.
1. Most important besides excessive valve clearance, where the shim can fall out, is not to have a tight valve (no clearance).
2. Jess opening advice is in inches.
I always remember that 1mm = 40 thou of an inch. So that if we are thinking in inches each shim size goes up in 0.002" or 0.05mm.
3. I always use clearances of 0.004" to 0.006"
4. I do believe there is a difference between the 270 and the 270A shim. I know it's not significant, however, the reason escapes me! It could be that, the "A" is on the high side of the shim tolerance.

Regardz.

It's hard to 100% estimate what shims you need first time around, but I'd do it this way. Try to insert the .05mm feeler constantly throughout the entire rotation of the cam on each valve. If it can be inserted at any point, use that as your reading (assuming the .10mm feeler cannot be inserted). On any valve you can insert the .05 then depending on what clearance you want, subtract one or two shim sizes. If you can insert a .05mm, but not a .10, I'd generally go down one size, so now hopefully you can insert a .10 but not a .15 feeler meaning your clearance is somewhere between the two where it should be. Don't bother using in between guages like .07mm, .09mm, .12mm ect. This is just a major waste of effort. Use only guages that go with the shim variations which are .05mm, so use only a .05, .10, .15mm feeler to go about this.
On any valve where there is no place even a .05mm guage will fit, try turning the bucket where the valve shim is with your fingers as you turn the cam. If the bucket can be turned easily, you can assume there is at least minimal clearance, somewhere between 0 and .05mm so I'd generally go down 2 sizes on the shim. On a valve that the bucket is hard to turn you can try 3 shim sizes. This should get you pretty close.

If you plan on making yourself into a self reliant sort, the least expensive way is to purchase a "kit" of shims from Z1enterprises.com. The shims Jeff sells in a kit form are less expensive than those available at a Kaw dealer (if they have them at all) and the kit will include a 2.00mm shim. A 2.00mm shim is handy for computing the needed shim. In addition, I doubt there is much difference between the shims with the A and those without. I use either a micrometer or digital caliper and check each shim I install because some numbers are a tad hard to read and a previous install may have had the shims installed number side up; further making the numbers hard or impossible to read. Install new shims number side down so the numbers don't get knicked off. The shim kit sold by z1enterprises.com gives you an assortment of shims in each size I think...

concerning the matter of what size shims to use if zero clearance is encountered,i have found that if you ask nicely, many bike shops will let you trade shims. i use a bike salvage shop that lets me pick through a big box of shims and replace the ones i use with ones i took out. check around in your area and maybe you'll get lucky and save time as well as money!!

Well I picked up a 2mm shim from the local dealer today for $10.95. My plan is to use this one to measure the gap accurately on each valve, so I can order the proper shims to get back to the spec tolerance.

The parts guy said that they will exchange shims for $5 each, which seems a little crazy to me. I wonder if I would get a different answer from the service department. At this point I'm going to just determine which ones I need and buy them from z1enterprises for $4.67 each instead.

Thanks for all the advice so far -- I'll post any interesting results from this process as I get further along.

Ive measured the change in opening and closing points for the valves using a degree wheel and dial and when u run 2 thousands or less the intake valve stays on the closing ramp longer and it closes at around 80deg instead of the normal 70. The drop in compression is around 35lbs. The power band shifts up higher while orgue is lost. I meant to say that. I used to run 1 thousands. U take a performance cam and set clearance at 8thou. The motor will choke its mixture off early limiting top end power and max torgue.

Nads, what are you telling us?
How can we use this info?
Should we give more clearance on a standard cam-shaft?

What would you say, is the optimum clearance for the best performance of a standard Z1 engine (cam-shaft).

On my older 80 kz550, Jeff at Z1 was nice enough to swap some higher number shims out of the kit with some more lower ones to fill the gaps. Jeff is such a great guy and I'd recommend talking to him. He'll help you, more than you could imagine!

When the clearance is too tight the compression drops due to the intake closing late. When this happens low and midrange power is lost while the peak horsepower occurs at a higher rpm. This peak horsepower however, can be less than stock. .004 is an excellent choice as the lifter will stay on the ramps smoothening opening and closing events as desighned.When clearance is too tight, the valve will open sooner and close later resultantly, Increasing the duration and shifting the power band higher into the rpm range. The key to speed and or power is to move an object from point a to b as fast as possible, wich means max torgue applied over distance and rpm is a result of that distance and of time. When torgue gets u moving rpms increase. When this increase occurs torgue may not continue to follow. This is the point at which ignition timing must be retarded or cam duration must be changed and lenghtend. A broad power band is key to broad performance curves. This is the way the bike was desighned. Lenthening the duration with close clearance will decrease wheel turning torque and a to b time is longer.

nads.com - Not familiar with the term "lifter" or "ramps" relative to a KZ. What do you mean by these terms? Thanks