The OBSERVED Valve Clearance thread

I left it as is. The fact that the next morning was the first sunny day in ages and I'd arranged a burn out with my mate, who'd just bought a new Bonnie T120, might have had some thing to do with it ;-)

I have to agree with 736, as well as Ulvetanna. Not worth the risk and a tad loose isn't such a bad thing.

I'll see if they move any more next year...
 
beardyweirdy@me.com_imp said:
I left it as is. The fact that the next morning was the first sunny day in ages and I'd arranged a burn out with my mate, who'd just bought a new Bonnie T120, might have had some thing to do with it ;-)

I have to agree with 736, as well as Ulvetanna. Not worth the risk and a tad loose isn't such a bad thing.

I'll see if they move any more next year...
Click to expand...
Sounds about right, see what they look like next checkup.
 
Clearance at 17.000 km ( first time check ) cb1100 2010 japan import with 7.500 after 7 years.
Used 300 cc. oil over 5.000 km but has used 75 cc since last change ( both times full synthetic ).
Everything looked pristine and shiny, no oil deposits anywhere, very clean inside.
There is a bit of residual oil stuck between the cam lobes and the buckets that has to be good for first startup lubrication, nice bonus, and the cover went on much easyer than taking it out, the coil spade connectors rubber boots go much easyer on with a little grease on the inside of the rubber boots and protect the connectors from water over the little edges on the coil terminals.

spec; ex 0.28 in 0.15 +/- 0.03 mm.


#1 - exhaust .28,.28 intake .16,.17
#2 - exhaust .28,.28 intake .15,.16
#3 - exhaust .27,.27 intake .18,.18
#4 - exhaust .28,.28 intake .16,.15

No adjustment needed.

max
 
OK, I have a question. People refer to these measurements as "loose" or "tight", assuming that the larger measurements mean loose and the smaller mean tight. I always assumed that meant the valve didn't open very much when tight and opened more when loose. However someone explained to me the opposite is true, what we are measuring is valve LASH, the distance between the tip of the lifter or cam lobe and the rocker arm? So that a wider gap means the valve opens LESS because the lifter/lobe has to move further before it contacts the rocker and moves the valve. A smaller gap means that the lifter/lobe contacts the rocker quicker and therefore opens the valve MORE as they move through their travel. Does this make sense?
 
jimgl3_imp said:
Ult, can't the shims be fished out without pulling the cams? or is that not possible with this motor?
Click to expand...
In this motor the shims are under the "buckets" atop the valves. The cam shafts must be removed in order to access. On an engine with the shims on top they are removed easily by compressing the valve spring and pulling them with a magnet.
DaSwami_imp said:
OK, I have a question. People refer to these measurements as "loose" or "tight", assuming that the larger measurements mean loose and the smaller mean tight. I always assumed that meant the valve didn't open very much when tight and opened more when loose. However someone explained to me the opposite is true, what we are measuring is valve LASH, the distance between the tip of the lifter or cam lobe and the rocker arm? So that a wider gap means the valve opens LESS because the lifter/lobe has to move further before it contacts the rocker and moves the valve. A smaller gap means that the lifter/lobe contacts the rocker quicker and therefore opens the valve MORE as they move through their travel. Does this make sense?
Click to expand...
Exactly.
 
redbirds_imp said:
jimgl3_imp said:
Ult, can't the shims be fished out without pulling the cams? or is that not possible with this motor?
Click to expand...
In this motor the shims are under the "buckets" atop the valves. The cam shafts must be removed in order to access. On an engine with the shims on top they are removed easily by compressing the valve spring and pulling them with a magnet.
DaSwami_imp said:
OK, I have a question. People refer to these measurements as "loose" or "tight", assuming that the larger measurements mean loose and the smaller mean tight. I always assumed that meant the valve didn't open very much when tight and opened more when loose. However someone explained to me the opposite is true, what we are measuring is valve LASH, the distance between the tip of the lifter or cam lobe and the rocker arm? So that a wider gap means the valve opens LESS because the lifter/lobe has to move further before it contacts the rocker and moves the valve. A smaller gap means that the lifter/lobe contacts the rocker quicker and therefore opens the valve MORE as they move through their travel. Does this make sense?
Click to expand...
Exactly.
Click to expand...
Succient explanation, redbirds.

Although a time consuming adjustment, when actually needed, the first link may help explain why Honda used the shim under bucket design:

https://paradiseracing.com/blog/why...ifter-buckets-larger-diameter-lifter-buckets/

The second link has a good comparison photo:

http://www.koracing.net/productimages/Buckets.jpg
 
Shim under bucket has a MUCH less chance of “tiddlywinking” when over-revved.
Shim under bucket has MUCH less wear on associated parts which equates to not going out of spec for valve clearance.
Shim under bucket is MUCH more involved to adjust clearance.
Shade tree mechanics probably risk doing more harm than good and should not remove cams in super skillfully built professional factory built engines, and trusting someone else to do so has its risks as well. They are PERFECT from the get-go.
Only abused, over-revved, dirty oil, high mileage modern Japanese motors ever require valve adjustment. Even then, they won’t break or have catastrophic failure. Motocross singles are the exception, they need regular adjusting and rebuilding.
 
Thank you for saving us money .
SportsterDoc_imp said:
redbirds_imp said:
jimgl3_imp said:
Ult, can't the shims be fished out without pulling the cams? or is that not possible with this motor?
Click to expand...
In this motor the shims are under the "buckets" atop the valves. The cam shafts must be removed in order to access. On an engine with the shims on top they are removed easily by compressing the valve spring and pulling them with a magnet.
DaSwami_imp said:
OK, I have a question. People refer to these measurements as "loose" or "tight", assuming that the larger measurements mean loose and the smaller mean tight. I always assumed that meant the valve didn't open very much when tight and opened more when loose. However someone explained to me the opposite is true, what we are measuring is valve LASH, the distance between the tip of the lifter or cam lobe and the rocker arm? So that a wider gap means the valve opens LESS because the lifter/lobe has to move further before it contacts the rocker and moves the valve. A smaller gap means that the lifter/lobe contacts the rocker quicker and therefore opens the valve MORE as they move through their travel. Does this make sense?
Click to expand...
Exactly.
Click to expand...
Succient explanation, redbirds.

Although a time consuming adjustment, when actually needed, the first link may help explain why Honda used the shim under bucket design:

https://paradiseracing.com/blog/why...ifter-buckets-larger-diameter-lifter-buckets/

The second link has a good comparison photo:

http://www.koracing.net/productimages/Buckets.jpg
Click to expand...
Succient explanation, redbirds.

Although a time consuming adjustment, when actually needed, the first link may help explain why Honda used the shim under bucket design:

https://paradiseracing.com/blog/why...ifter-buckets-larger-diameter-lifter-buckets/

The second link has a good comparison photo:

http://www.koracing.net/productimages/Buckets.jpg My CBX's had shim over bucket (24 !) but I never had problems because I never over revved the engines , they were quite easy to change with the right tools.
 
redbirds, if you can't fish them out i'm thinking it's due to 4 valves per cylinder, because i've seen with old 2 per motors that you can block the valves from returning through the spark plug holes and fish the shims out. i don't think a magnet is a good idea ever though. as the first step should be making sure your tools are demagnetized. ??
 
Actually jimgl3, the manual says to use magnetized tools to remove the bucket (lifter) and the shim. And a warning not to drop them into the engine...

There is no fishing them out. You have to remove the cams to remove the buckets to get to the shims. Thats it. My ST1300 is the same way. Shim under bucket. Cams come out to adjust.
 
736cc_imp said:
Shim under bucket has a MUCH less chance of “tiddlywinking” when over-revved.
Shim under bucket has MUCH less wear on associated parts which equates to not going out of spec for valve clearance.
Shim under bucket is MUCH more involved to adjust clearance.
Shade tree mechanics probably risk doing more harm than good and should not remove cams in super skillfully built professional factory built engines, and trusting someone else to do so has its risks as well. They are PERFECT from the get-go.
Only abused, over-revved, dirty oil, high mileage modern Japanese motors ever require valve adjustment. Even then, they won’t break or have catastrophic failure. Motocross singles are the exception, they need regular adjusting and rebuilding.
Click to expand...
What do folks consider over-revving? I assume you aren’t just referring to redlining.
 
Can you guys who have checked your valve clearances tell me a little about the gauge you used, where you bought it, and how much it cost? Most of you have recorded your results in millimeters, and I would like to know if your gauges have .01mm increments. I have both metric and standard feeler gauges. My metric set has .05mm increments (.002 inch), and my standard set has .001 inch increments (.0254 mm). My VFR800 has a +/-.001 inch tolerance on the valves also, and I have been successfully using the standard gauges for my valve adjustments. I could get a more accurate measurement with metric gauges if they were available in .01mm increments. Thank you.
 
There is almost nothing easy with Google ...
 
Houtman_imp said:
Try NAPA , Snap On or McMaster ; otherwise just Google and you should find them easily.
Click to expand...
I stopped at my local NAPA dealer and he handed me their catalog and told me to pick out the one I wanted - I didn't see anything suitable. I looked on Amazon, and didn't find anything either. It was suggested to me to go to McMaster-Car.
 
Dave

All you need is a common feeler gauge.

Specs from post one:

EX: 0.28 +/- 0.03 mm (0.011 +/- 0.001 in)

IN: 0.15 +/- 0.03 mm (0.006 +/- 0.001 in)

Exhaust is within spec from 0.010 to 0.012"
If a 0.010" won't go, it is too tight.
If a 0.013" will go, it is too loose.

Intake is withing spec from 0.005 to 0.007"
If a 0.005" won't go, it is too tight.
If a 0.008" will go, it is too loose.
I have an ancient Neuses set on a key ring.
It only has nine gauges:
0.015
0.012
0.010
0.008
0.006
0.004
0.003
0.002
0.0015

For the intake,
the 0.002 and 0.003 together will check 0.005"
the 0.003 and 0.004 together will check 0.007
the 0.006 and 0.0015 will check for 7 1/2 thousandths
Due to the Neuses being on loan, when I had my Moto Guzzi, I bought an OEM from AutoZone for $6.99.

Its gauges include 3,4,5,6 &7 thousandths. All are marked in thousandths and in millimeters.

https://www.autozone.com/clamps-and...ge/oem-26-blades-master-feeler-gauge/1927_0_0
 
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