1st valve adjustment on this '78 kz1000

I'm getting ready to replace valve shims on my 1978 kz1000 A2 (standard) model, and I am about 100% sure this will be the first time for this bike as I'm the 2nd owner and the original owner was elderly, a bit crazy and lazy when it came to maintenance. Which may be well within acceptable operating parameters for an elderly biker. (I'm not sure as I'm an 'old' biker, not elderly though -- yet.)


I think I know the answer to this -- but will ask anyway -- what stock, standard shim sizes am I going to find when I remove the original factory-installed shims?

I'm replacing about half the shims due to insufficient clearance between the cam lobe and the shim (needs to be .05mm to .10mm, and 4 of mine are a bit less than .05mm).

So I *know* I'm going to install, most likely, the next smaller size shim on these 4 out-of-spec shims.

Just wondering -- what stock, standard shim sizes am I going to find when I remove the original factory-installed shims?

Why not just open her up and check? It's not a big job to remove a shim and measure it--if you have the right tools. You'll need the special shim remover tool and a micrometer to measure the thickness.

As far as I know, there is no way to predict what size of shims were used from the factory. But I THINK they shoot for somewhere in the mid range (240-270). But I'm not positive on that.

They used whatever shim they needed from the factory. There isn't a standard size they used for all of the valves. the only way to know is to pull the shim and take a look.

I have seen a lot of 270 sized shims. I mean a lot. Roy

hopefully your origional ones are on thicker end of scale so you have plenty of adjustment left in there,remember exhuast side needs more clearance than intakes since they run hotter

PLUMMEN wrote:

hopefully your origional ones are on thicker end of scale so you have plenty of adjustment left in there,remember exhuast side needs more clearance than intakes since they run hotter

I measured and found the following today -- - I used the .038mm, .051mm, .0635mm and .076mm feeler gauge leaves to check:

INTAKE
#1: .038mm/.051mm/.0635mm fit, .076mm DOES NOT FIT
#2: .038mm/.051mm/.0635mm fit, .076mm DOES NOT FIT
#3: ALL FIT (.038mm to .076mm)
#4: .038mm fits, .051mm *barely* fits, .0635mm and 076mm DO NOT FIT

EXHAUST:
#1: ALL FIT (.038mm to .076mm)
#2: .038mm/.051mm fit, .0635mm and 076mm DO NOT FIT
#3: .038mm/.051mm/.0635mm fits, .076mm DOES NOT FIT
#4: ALL FIT (.038mm to .076mm)

With the data above I only removed the #4 intake shim and the #2 exhaust shim.

The #4 intake shim read '230' and the #2 exhaust shim read '275' -- so I'm going to a 225 and a 270 as per the FSM to increase the clearance on those 2 valves -- is that logical?

While these 2 valve were *technically* in range since both cleared .05mm, that's the very minimum clearance -- they did not clear the next .0635mm feeler leaf -- and I don't want to have to open it up again in 3 months just to have to do the shim swap above (in Silicon Valley we can ride all winter), I *know* I'm going to need to increase the clearance on these 2 valves PDQ anyways, may as well do it now while she's open.

I agree. When the clearance is barely wide enough to be in spec, I throw in the next thinner shim as well to go to the higher range limit on gap. Being a thou too wide won't hurt anything, but insufficient clearance can destroy the valve seats.