Exhaust valves too tight

Discussion in 'Maintenance' started by mickey, Jun 9, 2019.

  1. mickey

    mickey New Member

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    Ok so finally got chance too do a valve check on my 05 cbr1000rr intake valves are in spec but the exhaust valves are out more so number 3 cylinder which is not running right which lead me too doing the valve check the tolerance should be 0.27 too 0.33 number one cylinder is 0.25 so is number 2 & 4 but number 3 is 0.15 0.20 is there any way of adjusting the valves too bring them back in tolerance??? Any advice plz on what I should do I’m planning on doing a compression test this afternoon if the weather holds off
     
  2. Selmer50mark

    Selmer50mark Active Member

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    Basically you need a Haynes manual to guide you
     
  3. Bikeboy

    Bikeboy Member

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    Arent they shims? Remove the cams .swap for a thinner shim and replace the cams. Recheck to find out you've measured it wrong and it's now worse than it was before you started ? :eek:
     
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  4. bazzashadow

    bazzashadow Active Member

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    Yep you need new shims
    Don’t ask what sizes
    I had a mechanic do my VTR
     
  5. Grooveski

    Grooveski New Member

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    Presuming the cam position sensor and camchain tensioner are already off, the process goes like:

    Make a diagram with all 16 valves individually numbered and space for four or five sizes beside each valve.
    Measure everything again to be sure and write the gaps on the diagram.
    Crank the engine to where the camshaft sprocket marks are lining up with the top of the case.
    Unbolt the shaft clamps slowly in the order shown in the manual.
    Tie up the camchain to the frame.
    Remove the shafts.
    Lift the buckets off the valves that need adjusted with a magnet stuck right in the middle of the bucket. The shims should come out along with them(all eight that I lifted did anyway - if you're wary, stick rags or paper towels down all the nooks and crannies before you start pulling the buckets).
    Mark each shim and bucket as you remove them. Bits of masking tape work well with the valve numbers written on them.
    Measure the shims with a micrometer - write the sizes onto the diagram.
    Check to see if any of the old shims can be moved to another valve to bring it's gap into tolerance.
    Write the desired new(thinner) shim sizes onto the chart. Original shims you're taking out will be in 0.01 increments but most likely the replacements will be in 0.05 increments. Also write down what the resulting gap will be.
    Double check everything.
    Exchange or buy new shims.
    Pop them into place.
    Squirt everything with oil during reassembly.
    Slip the buckets back on(...in their original positions)
    Camshafts back in - inlet mark will be three or four mill high, exhaust mark will be slightly low as the shaft will be coming down at an angle.
    Tighten down the shafts as per manual.
    Slip a finger into the tensioner hole to push the blade back out(or the loose chain might jump teeth when you next crank the engine). I was just doing this as a matter of course whenever I cranked it over as the blade itself doesn't have as much spring as some others do.
    Check timing marks.
    Check the clearances. Tick them off on the diagram.
    Job's a good 'un.

    Check out the last few minutes of this video for a handy trick for refitting the tensioner.
     
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  6. nigelrb

    nigelrb Senior Member

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    Excellent help, Grooveski. That's what makes forums such as this so worthwhile.
     
  7. Grooveski

    Grooveski New Member

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    Just thought I'd add a link to the exploded view that was handy when my "which bolts go where" notes didn't make as much sense as they had the day before when I'd written them.
     
  8. tony sawyer

    tony sawyer New Member

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    just out of interest how many miles has your bike done
     
  9. mickey

    mickey New Member

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    22700 I have looked in the history of the bike too see if the valves had been checked at 19k but nothing
     
  10. mickey

    mickey New Member

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    M8 you have been a great help in exsplaining the procedure it does sound a scary job to do and I’m very tempted in trying it my self I’m sorry for the delay in responding been very busy at work thanks for all the help no doubt I will be back on here soon
     
  11. Grooveski

    Grooveski New Member

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    Mickey asked for some clarification of the size checking so thought I'd copy the reply here because:
    a) Other folk may be curious.
    b) I'm no expert and am a little nervous encouraging somone else to tear their top end apart - so if I mess up or miss something hopefully someone will point it out.




    If you have a gap that's small by say 0.02mm you want to measure the shim then replace it with one that's thinner.
    0.02 thinner would bring the gap to the tight edge of the range
    0.05 thinner would bring the gap to the middle of the range.
    0.08 thinner would take the gap to the open edge of the range.

    Here's the chart from when I done mine. It started with just the circles and valve numbers.

    https://i.postimg.cc/FKYkhXn4/IMG-7653.jpg

    The first number out from the circle is the original gap size.

    A cross in the circle means the gap is out of tolerance.
    A dot in the circle means the gap is tight and will be out soon. Doing these now means I shouldn't have to change any for a good while.

    Next number out is the existing shim size.

    Next number out (the ones in boxes) is the replacement shim size.

    The next number (mostly scored out) was the expected final gap size.

    Last number is the measured new gap once it was all back together. In a few cases the gap was very slightly tighter than expected(which is pretty normal).
    ...and in one case(valve 10) was a lot tighter than expected. I think a speck of dirt might have got in. It's in range though and if it is a bit of dirt it'll hopefully get pulverised and the gap will still be within range.

    You'll see a lot of gap sizes written to three decimal places. I wasn't actually measuring to 3 places - it just means the bigger gauge didn't fit but the smaller one was pretty loose(so 0.185 means 0.19 didn't fit and 0.18 was loose)

    ...so yeah - reading the diagram goes like:

    Valve 6 - original gap was 0.28 - original shim size was 1.92 - replacement shim size was 1.90 bringing the gap up to 0.30
    or
    Valve 16 - original gap was 0.14 - original shim size was 2.12 - replaced it with the 2.10 shim taken from valve 14 bringing the gap up to 0.16

    Remember to number the buckets and replace them on the same valves as before - there's no guarantee that they're all the same thickness so if you mix them up it'll mess everything up.
     
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  12. hitch

    hitch Well-Known Member

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    WOW...this is far, far out of my comfort zone.
    Fair play for doing it and massive kudos for your input on this thread.
     
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  13. nigelrb

    nigelrb Senior Member

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    Totally agree.

    Fairly confident that @Grooveski would end up with a better job than if performed by most dealers too.

    For me, I could do it, but I have a problem with lacking patience. I'd do the first three perfect, and the next three pretty close, and the final 10 would be a haphazard 'she'll be right, mate' attitude.

    BUT, I'm not like that with a yellow cloth and can of Mr Sheen!!:rolleyes:
     
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  14. Grooveski

    Grooveski New Member

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    This was my first bucket and shim job so I wasn't exactly comfortable to begin with either. :) Have done other clearances though(screw and locknut on my old VT, funky little spring-loaded rocker arms on the ZXR that slide aside to let you into the shims) and had changed a couple of camchains(involving lifting shafts) so had the background for all the bits of job - just hadn't done them all at the same time.

    Patience is essential. The shambles on the diagram at valve 2 came late in the evening, I was getting tired and a bit punchy and measured the gap wrong(had a wrong feeler in the stack). When I realised what had happened I downed tools for the night and went through everything again the next morning.
     
    #14 Grooveski, Jun 20, 2019
    Last edited: Jun 20, 2019
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  15. Black & White

    Black & White New Member

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    Good description, Groovsky.
    I can't stress enough, making sure the cams are timed is critical. I mean, destroy your engine if it's wrong, critical.
    Once you've got the cams & sprockets all in, make sure you turn the engine over by hand two turns of the crankshaft. If you feel any resistance, it could be the valves contacting the pistons. Don't force it because (with the spark plugs out & out of gear(!)) it should turn quite easily.
    If it stops turning, go back & recheck the valve timing - do this before using the starter button!
     
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