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Offline AvgBear

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Re: Shim set adjusting valves
« Reply #20 on: February 06, 2019, 10:25:47 PM »
*Originally Posted by Rorut [+]
Is 0.260 considered harmly out of spec?
Exh. valve clearance less than 0.325mm is out-of-spec.
Less clearance means less time the valve face has resting on the valve seat shedding heat into the cyl. head & cooling system.

*Originally Posted by Rorut [+]
And can 6000miles really make a difference related to my measurements?
Valve clearances on modern engines with today's metallurgy tend to change slowly (if at all) once set properly.
All other things being equal, etc.
"Working on a motorcycle, working well, caring, is to become part of a process, to achieve an inner peace of mind.
The motorcycle is primarily a mental phenomenon."
Robert M. Pirsig

Offline Rorut

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Re: Shim set adjusting valves
« Reply #21 on: February 06, 2019, 10:42:49 PM »
*Originally Posted by AvgBear [+]
Exh. valve clearance less than 0.325mm is out-of-spec.
Yes but jut wondered if my differences could have harmed the bike. It looks like its a pretty big change there, but I dont know, first time doing this...

*Originally Posted by AvgBear [+]
Valve clearances on modern engines with today's metallurgy tend to change slowly (if at all) once set properly.
All other things being equal, etc.
Starting to think that the workshop previous owner hired skipped the valve measurents completely. I had my dad over and we both checked every valve several times to be sure measurements correct.
The bike just passed 24K. Can it be out of tolerance already leaving factory?

Offline Rorut

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Re: Shim set adjusting valves
« Reply #22 on: February 07, 2019, 07:27:28 AM »
Another thing. For the new shims I planned midrange but is it not better to put in shims for a bit more loose setup for a bit better planning when doing this next time?

Offline AvgBear

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Re: Shim set adjusting valves
« Reply #23 on: February 07, 2019, 04:37:24 PM »
*Originally Posted by Rorut [+]
Yes but jut wondered if my differences could have harmed the bike.
The ways to answer that would be if performance has been affected: loss of power/top speed or a dynomometer run to check the output graphs against known standard output graphs.
Another answer would be to disassemble the cylinder head and physically inspect the condition of the valve face/s and valve seat/s.

*Originally Posted by Rorut [+]
I had my dad over and we both checked every valve several times to be sure measurements correct.
The bike just passed 24K.
Can it be out of tolerance already leaving factory
Apparently, yes -- you and your dad determined that.
If you didn't buy the bike new -- you can't be sure what has or hasn't been done.
Valve clearances could've also been mal-adjusted (adjusted incorrectly).
That's why it's important to check valve clearances (by you or someone you trust) -- only then will you know.

*Originally Posted by Rorut [+]
Another thing. For the new shims I planned midrange but is it not better to put in shims for a bit more loose setup for a bit better planning when doing this next time?
I would say: not unless you see a pattern in that direction -- and keeping a record of measured clearances and shims changed is the way to do that.
Mid-range clearance is probably the ideal -- but, if you must err (say, the exact size shim you need for mid-range isn't available), then err in the more clearance direction - yes.
"Working on a motorcycle, working well, caring, is to become part of a process, to achieve an inner peace of mind.
The motorcycle is primarily a mental phenomenon."
Robert M. Pirsig

Offline herdygerdy

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Re: Shim set adjusting valves
« Reply #24 on: February 07, 2019, 08:00:24 PM »
Totally agree with AvgBear's comment re mid-range clearances and erring on the wider clearances.  I have 24 of the pesky things to do on my classic Honda CBX 6 (shim OVER bucket fortunately) and ALWAYS set them to the maximum factory recommended clearance.

As AvgBear said, a larger valve clearance allows more time for the valve head to be "at rest" on the valve seat.  This gives more time for the latent head building up in the valve head to transfer through the valve seat to the cylinder head and then be carried away by cooling oil and water. It helps the valve run much cooler, compared to one with clearances set 'tight'.   Particularly important for the much hotter exhaust valves.

On the CBX engine, heard many times of folks setting clearances on a fresh valve train 'nice and tight' to get a quiet motor, only to burn out exhaust valves withn 1,000 kms. 

Any little thing you can do to help the valves run cooler is very good for the longevity of your engine.  And good on you for having some quality shed time with your dear old Dad doing the valve check and adjust yourselves.


Offline Rorut

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Re: Shim set adjusting valves
« Reply #25 on: February 08, 2019, 01:25:25 AM »
Thanks a lot for helping with interesting reading.
I got three measurements wrong (ofcourse).
Having a difficult time with the feeler gauges. I felt it much easier now on exhaust side bending them 90 degrees. That makes the blad go straight in under. Before I had them bent like a banana and I had them stuck just at the point in the beginning. Intake is more flexible because of thinner blades and not any tight angles like exhaust side.
The angle in combination with the thicker blade not bent correct made it very difficult.
I cant imagine you do them with straigt feeler blades??

Offline Rorut

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Re: Shim set adjusting valves
« Reply #26 on: February 08, 2019, 09:08:50 AM »
I first had it more like A. Problem getting them in. Then changed to B and blades went in that did not before....
exhaust:

Offline Rorut

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Re: Shim set adjusting valves
« Reply #27 on: February 09, 2019, 02:55:30 PM »
Having them bent like this feels like it will give a more reliable result...

« Last Edit: February 09, 2019, 02:58:51 PM by Rorut »

 


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