TOPIC:

I was checking the clearance on my 78 KZ650 and can't slide the smallest feeler gauge (.038 MM) in all but one valve (.125 MM). I did a search on the forum and read if the clearance is too small, the valves burn up. Can I check the valves without pulling the head? To get them back to spec, do I put in the smaller shims to get at least a clearance reading?

Compression - 140 140 135 140

I just bought the bike for cheap and don't know the history. I'm thinking no valve adjustment was done and the valve seats are pooched or the valve adjustment was not done properly. When I pulled the carbs, they were all out of wack too.

Yes you can check clearances without pulling the head off. That is what you are doing by sticking feeler guages in there.

As far as clearance, it sounds like you are trying to use feelers that are way to thick for what you need here. On my CSR 1000 the clerances should be .005mm to .015mm. That way smaller than .038mm. Your compression numbers are pretty good!. Chances are if the problem is it wont run the carbs are gummed up from sitting so long.

Correct clearance is .10mm-.15mm (.004"-.006").

Here is a page with the major specs for you bike,,

With those compression numbers I wouldn't worry about the valves, those numbers are pretty decent.

Correct specs should be 0.003 - 0.007 in.(0.08-0.18mm). The smallest gauge I have is .038 MM (millimeter) so my clearances are way too tight.

Should I pull the head to check the valves and seats?

No, don't pull the head; as Steell mentioned those numbers are ok and nothing you mentioned yet would make me want to pull the head before doing a valve clearance adjustment. After an adjustment those compression numbers may go up too.

Pull the cams and see what shims are on each valve, they are marked with a number. If not marked then measure them with a metric micrometer. I think you will be switching shims at least 2 sizes smaller, maybe 3 sizes.

Don't mix them up, keep them separated in an egg carton. Use the chart here to figure out your new shim size.

You may be able to swap shims around for a few valves. When you figure out what shims you need from that chart, take the shims you can't use to your Kawasaki dealer and talk to a mechanic about swapping shims. My dealer's mechanic does it for free, lot's of them do, some don't, you may spend 5-7 bucks a shim too.

AutoXN wrote:

Correct specs should be 0.003 - 0.007 in.(0.08-0.18mm). The smallest gauge I have is .038 MM (millimeter) so my clearances are way too tight.

Should I pull the head to check the valves and seats?

The fact that you are holding compression proves the valve clearance must be greater than zero... and the fact you can not get the feeler gauge of size 0.38mm (.0015" ) under them says the clearance must be between ZERO and .0015".

Shims for mine come in steps of .002" (.05mm) so it sounds like you need to go two sizes thinner on every valve in the ZERO - .0015" range, which will up the clearance to .004" - .0055". You may be able to swap some shims around and not have to replace a lot. maybe not, keep the shims sorted to the valves and you can make a list of the sizes you need to get proper clearance.

FWIW: The Craftsman metric feeler gauge thinnest blade is .052mm which comes in handy for measuring clearances as they have them in .025mm increments after... next one up is .078mm then .102mm etc (or something very similar).

I am not sure you will burn valves if there is no clearance... you will just cause the valve to hang open and will get no compression because the combustion chamber isn't sealed. I can't imagine what good it would do to remove the head to measure clearances... You can do the measurement part by just removing the valve cover and aligning the cams per your manual for each valve. If you find a shim with less clearance than is called for based on the Kaw spec (I don't know what it is for a 650 but would rely on a manual), then you will need to remove your cams and remove the bucket for that valve. The 650 shim is about the size of a dime and located under the bucket. Make sure you orient the engine to TDC for #4 cylinder before you remove the cams as this makes it easier to reinstall them I believe.

wiredgeorge wrote:

FWIW: The Craftsman metric feeler gauge thinnest blade is .052mm which comes in handy for measuring clearances as they have them in .025mm increments after... next one up is .078mm then .102mm etc (or something very similar).

I got a set that starts at .001" (.025mm) and has .0015, .002", .003", .004".... max is .015".

Pretty handy for doing valves because you can go all the way down to a thou and the .0015 blade lets you measure half thousandths by pairing it up with other blades so you can tell which way it's leaning in between blade sizes.

I will check the clearances again just to make sure. I was using a Lisle feeler gauge which should be accurate. The bike runs very well now and compression is good.

Thanks everyone for your help!

I'll post my method for checking clearances in case you haven't read it. I try for .10-.15 range on the clearances. The way I do it, and this came right from a factory Kawasaki mechanic is to turn the engine over slowly with your 17mm wrench on the end of the crank while constantly trying to insert a .10mm feeler between the cam and bucket. If anywhere throughout the entire rotation, it can be inserted, try a .15mm feeler and see if it can be inserted anywhere throughout the rotation. If the .10mm cannot be inserted, try the .05mm. The key here is to only use feelers in increments of .05mm because that's the size the shims are available in. When you find which feeler fits and which one doesn't we call that the clearance. So if a .10mm fits, a .15 does not, our clearance is considered .10mm. Do this for each valve. To me this is the only logical way to approach it, as I don't care if clearance is really .10mm, or .12mm or .13mm because shims are only available in .05mm increments. This way you really need only a .05, .10, .15 and .20mm feeler, none of the others do you one bit of good. This is all debatable and others don't like my procedure, and that's fine doing it by the book too.

The one thing I'm sure no one can contest though is to change shims on a KZ650 there is no need to ever completely remove the camshafts. This eliminates the need to even care where you position the engine, but it's still best to have the timing marks for the camshafts lined up with the front and rear of the engine in case of mishap. Doing it this way there is no need to retime the engine. The way to do it is to remove your center camchain sprocket from between the camshafts, then unbolt only one camshaft. Carefully lift it up keeping the chain tight going down in the engine and move the camshaft to the center of the engine. Be sure and keep chain tight down into the engine and keep all slack between the camshafts. Change your shims on those valves, carefully move the camshaft back into place keeping the chain tight down the engine. Bolt the camshaft back in and you're done. Repeat on the other cam. Now if you've kept the chain always tight going down into the engine the timing is exactly where you left it and you're job is done.