Valve Noise/No compression

  • Patton
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Re: Valve Noise

15 Oct 2013 09:54
#610064
Zero clearance when the valve is supposedly closed usually means the valve is always staying partially open, which will prevent compression from building inside the combustion chamber, because the compression is being lost through the partially open valve.

Another possible reason for zero compression is a hole through the piston.

What does the wet compression test show on #3 cylinder?

Good Fortune! :)
1973 Z1
KZ900 LTD

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  • BIGKEVIN
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Re: Valve Noise

15 Oct 2013 12:03
#610072
I didn't do a wet compression test. I am going to check the valve clearance again when I get home.
1976 KZ900
2006 ZX6R

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  • BIGKEVIN
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Re: Valve Noise

15 Oct 2013 12:11
#610073
If the valve clearance is too loose, can that cause a loss of compression ?
1976 KZ900
2006 ZX6R

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  • 650ed
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Re: Valve Noise

15 Oct 2013 12:22
#610074
Valve clearances being too loose should not reduce compression because that will not hold the valves open. Ed
1977 KZ650-C1 Original Owner - Stock (with additional invisible FIAMM horn)

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  • BIGKEVIN
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Re: Valve Noise

15 Oct 2013 15:09
#610087
Can the piston be checked for a hole in it with the head on or does it need to come off ? Can the pistion be checked for a hole by looking in the spark plug hole ?
1976 KZ900
2006 ZX6R

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  • Lt.Dan
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Re: Valve Noise

15 Oct 2013 15:31
#610090
BIGKEVIN wrote: I did a dry compression test today and have 140 psi from the #1 cyclinder, 120 psi from #2, 0 from #3, and 140 psi from #4. I just did a valve job and they are:
quote]

I still contend that the use of the fixed valve shim tool will bend valves if not used properly. My bet is you have a bent valve on #3

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Re: Valve Noise

15 Oct 2013 19:47
#610130
Is there anything else that can be checked before I pull the head off ? My concern with pulling the head is keeping the cams timed correctly.
1976 KZ900
2006 ZX6R

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Re: No compression on #3 cyclinder

15 Oct 2013 20:22
#610132
What is the correct exhaust valve and head gaskey that I need to order from Z1 ?
1976 KZ900
2006 ZX6R

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  • koolaid_kid
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Re: Valve Noise

15 Oct 2013 20:58
#610135
Not unless you have some sort of scope.
1983 GPz 750
810 Wiseco, Kerker, K&N, DynoJet S3, Accel, Progressive, etc.

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  • koolaid_kid
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Re: Valve Noise

15 Oct 2013 20:59
#610136
Timing the cams is very easy and explained in your factory service manual.
1983 GPz 750
810 Wiseco, Kerker, K&N, DynoJet S3, Accel, Progressive, etc.

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  • BIGKEVIN
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Re: Valve Noise

15 Oct 2013 22:01
#610143
Can the head be be removed from the motor while the motor is still in the bike ?
1976 KZ900
2006 ZX6R

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  • koolaid_kid
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Re: Valve Noise

15 Oct 2013 23:04
#610156
Sure. It is a PITA, but it can be done.
1983 GPz 750
810 Wiseco, Kerker, K&N, DynoJet S3, Accel, Progressive, etc.

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