Valve Clearance Measurement Question

From WG's article:

"You should be able to put a feeler gauge between the shim and camshaft and feel a slight pull. You shouldn’t have to force the gauge between the two surfaces. Use the appropriate sized feeler gauge to get this slight pull."

My question is how far between them should I be able to put it? The one valve I've tried measuring won't let the thinnest feeler gauge I have between them. Should I not be expecting to have the gauge slide between them even a little bit? I bought my gauge from z1 is that not the best one to use?

Little B wrote:

...The one valve I've tried measuring won't let the thinnest feeler gauge I have between them....

Then either you have absolutely no :blink: clearance, or you don't have the crank/cam turned to the proper alignment to allow testing for clearance...

if u have the cam lobe faceing away ,try to rotate the shim. if the shim moves at all, consider this as near 0 clearance, and reshim.sometimes u can rotate the cam a bit and the clearance will change slightly.

Thanks for the quick reply Biquetoast!

I'll check to make sure I have it lined up properly and see what I come up with.

mark1122 wrote:

if u have the cam lobe faceing away ,try to rotate the shim.

Thanks for the suggestion mark. I can't do that on my bike though because the shims are actually under the valve lifters.

Just finished re-checking how I had it lined up and re-measured. The smallest gauge I have is a 0.04mm. It doesn't fit. So, all four of my intake valves have between 0 and 0.03 clearance.

My exhaust valves are in better shape. 1 & 3 are both at 0.06mm. 2 & 4 are both between 0.11 and 0.14mm. Is it usual to have the valves that fire off in a pair have the same clearances?

Is my next step to take off the camshafts, lift up the valve lifters and find out what size shim are in there?

B, are you going at this without a manual? If so, you might consider getting one if not only for the illustrations. I've been able to understand the suggestions here better after looking in the manual as I've been able to understand the manual better by the suggestions here. Might be worth checking one out.

Little B wrote:...I can't do that on my bike though because the shims are actually under the valve lifters....

...Is my next step to take off the camshafts, lift up the valve lifters and find out what size shim are in there?[/quote]

I think you mean that the shims are under the buckets on your model.

If so, yes, you have to get the buckets off to get to the shims... glad I don't have to do that on mine! Be absolutely certain of your clearance measurements before removal, since it's a pain to re-measure...

KZErider wrote:

B, are you going at this without a manual?

Nope, I actually have two of them! :woohoo: One is for when I'm working on the bad girl and the other is for studying in 'cleaner' environments. You're right though, it makes things MUCH easier to understand. Thanks for the suggestion.

Biquetoast wrote:

I think you mean that the shims are under the buckets on your model.

If so, yes, you have to get the buckets off to get to the shims... glad I don't have to do that on mine! Be absolutely certain of your clearance measurements before removal, since it's a pain to re-measure...

Well, the manual calls them 'valve lifters'. They do look like buckets though! I am confident of the measurements I took since after measuring the exhaust valves successfully, I now understand what they are supposed to do when the gauge fits. The only thing I'm not sure of is where exactly on the 0 to 0.03 scale it fits since I don't have a smaller gauge.

This has turned into a big job. The thing that kills me is that I can't ride while she's lade up like this. I'm learning a lot & really appreciate all the help here though!

I've already measured the cam chain to make sure its within spec and it is. So, other than replacing the head cover gasket & cam plugs, should I do anything else while I'm in this part of the engine?

I've noticed that as I'm turning the crankshaft w/ the wrench, the chain is sometimes very taught between the two sprockets (front & rear) and at other times has a sag between them. Also, sometimes it takes more force to turn it than others. Is that all normal? Should I look at the tensioner after finishing with the valves?

I always measure the gap with what gauge will go in and what won't. For instance, if a .003 will go in but a .005 won't, then you've got a measurement of .004.

Make sure your cam timing is correct. Check the manual.

Little B wrote:

... as I'm turning the crankshaft w/ the wrench, the chain is sometimes very taught between the two sprockets (front & rear) and at other times has a sag between them. Also, sometimes it takes more force to turn it than others. Is that all normal? Should I look at the tensioner after finishing with the valves?

Perfectly normal.

The T mark on timing advancer unit is to show TDC (top dead center) when lined up with the case timing mark (where two pistons will be at TDC). This position is where the cam chain is slackest on its rear side, and allows the tensioner adjustment (pressing against rear side of cam chain) to attain the ideal setting. So the T mark is used when adjusting the cam chain tension.

The 17mm "nut" turns harder when pushing the crankshaft through the compression stroke. With spark plugs removed, would not notice as much difference during crank rotation. As known, the smaller bolt fitted into end of crankshaft should not be used to turn the crank.

Adjusting the cam chain tension is a routine maintenance item and cannot be done too often.

There are some excellent previous threads here on KZrider regarding detailed procedures for under-bucket valve clearance adjustments.

Good luck with the re-shimming!

Patton wrote:Perfectly normal.

Adjusting the cam chain tension is a routine maintenance item and cannot be done too often.
[/quote]

Thanks a heap Patton!! I feel better knowing that it is normal and understanding how things work better! That also explains why you have to pull on the cam chain when turning the crank if one of the sprockets are off.

Per the above quote: My bike has a wedge type automatic cam chain tensioner. My understanding is that it is supposed to self adjust. I was thinking that perhaps the springs are worn out and not pushing against the rod as hard as they used to. Would that explain the noise at startup and idle?

regarding the tensioner, do you recommend another approach?

Little B wrote:

... My bike has a wedge type automatic cam chain tensioner. My understanding is that it is supposed to self adjust. I was thinking that perhaps the springs are worn out and not pushing against the rod as hard as they used to. Would that explain the noise at startup and idle? regarding the tensioner, do you recommend another approach?

As known, the "automatic" feature of the automatic cam chain adjuster is allowing the spring to press the slider against the cam chain at the designed pressure, and it is not supposed to be too tight. Perhaps other have experienced weakened springs, but I have not.

The adjustment routine is best done with a warm engine and after kicking or spinning the crankshaft over a few times to loosen things up. Then line up the T mark with the casing mark. Next loosen the adjuster locknut. Then loosen the bolt (which frees the inside pushrod so the spring can move it forward at the designed pressure -- the "automatic" part).

Then tighten the bolt (which locks the pushrod in position), and next tighten the locknut (to keep the bolt in place). And not Godzilla tight on either bolt or locknut, as several folks have stripped these parts or broken off the bolt.

Often a good carb sync will smooth the idle enough to greatly reduce the nail-digesting rattle at low rpm.

Good luck!

Post edited by: Patton, at: 2007/12/03 09:48