Strange Vacuum Reading

Why don't you pull all your shims and check their sizes. It should be marked on the shim. So if you had a 2.85 that gave no clearance you want a smaller shim like a 2.80 or a 2.75. once you have some clearance you can measure and do the math to find the correct size that you need.

I have found engines with the correct shims but in the wrong buckets before.

what your vacuum gauge is missing is whats called a damper. in my case i built a 4 gauge unit using matched vacuum gauges and flow controls to dampen the pulsations. itll cost about the same to buy a real set or make your own...its up to you. heres a pic of the unit i made. its crude but it works great!!

bigkaw815 wrote:

I appreciate the response, but the problem is that my shims have no clearance to measure! That said, tables and charts will not help me.

Depends: if you can spin the bucket with your fingers, you have some clearance. Assume it's zero and adjust from there and you will be within a thou or so.

BTW, I found a set of feelers that go all the way down to .001" on line.

If it is stuck tight, you need to install a thinner shim and remeasure.

bigkaw815 wrote:

I wonder if I can take out the shims, install the buckets and cams, then measure the distance subtracting proper cam clearance?

I don't think so.

OKC_Kent wrote:

Proceed to check all the valves, then pull the shims out and use a mike or vernier caliper to measure the thickness (convert to millimeter); then apply the shim size and valve clearance to get proper shim from the chart.

I recommend making a drawing and writing down which size shims were where when you started.

As stated, measure the shims yourself. Then, I label them with a Sharpie to make life easier while I swap them around.

where are you located? maybe someone close by has some shims to play with??

Great replies all. I am in Pueblo Colorado and will pay the cost of the shims as new if I can forgo shipping. As an update, I pulled my carbs off today because I jacked them up with my ingenious one gauge idea. Did the mechanical synch and adjusted floats- man it ran great. Can't wait to ride it with the val valves adjusted

Shims pretty much come in steps of .5 (for the KZ900/1000 anyways)....

Question:
Not to insult, just insuring for one method will make a change in your clearance measurements...

When your rotating the cam lobe for measurements, what's the orientation of the lobe... 45 (side) or 90 degrees (heal) straight up?

Not sure about 650's but if measuring from the non heal, cam lobes are curved and can give you inaccurate measurements...

As mentioned, with the lobe orientation correct if you can spin the shim then you have some sort of clearance...

Ok, Pencil, paper, and caliper..... open her up and measure & record each shim thickness with your caliper. Insert them back to there location after measuring.

They are normally marked with their values, usually inserted with the marking side down so the lobe doesn't wear this data off... Doesn't matter though for you're going to measure them anyways.

From those values, subtract .5 to 1mm. or what ever the spec is for KZ650's...

Something I have been learning...
On the intakes be closure to the low spec on the intakes. For the exhaust, stay closer to the high end of the spec.

Reasoning, the exhaust get's the most heat and the clearances seem to fluctuate more than the intakes...

In either case, just get them into spec....

You can obtain shims @ Z1
www.z1enterprises.com/SearchResult.aspx?All=True&KeyWords=shim

Good luck, let us know how it turns out...

OMR

Are you using the factory service manual as a reference on how to check valve clearance? Ed

try this site I made one for under 3.00 $ faq.ninja250.org/wiki/How_do_I_synchroni...s%3F#Carb_sync_tools

This will be unwelcome but.... When measurable clearance between shim and cam,(bucket still spins)is too small to measure, it usually requires 3 sizes to either come to spec. or measure. The point is moot. at this point, valve face/seat is shot.and adjustments will be short-term. early valves were composite w/valve faces hard surfaced,later valves stellite faced. once facing/coating is gone, wear accelerates. valves are cheaper than seats you must be the judge.G