Can a mechanic just by listening and feeling the pressure from exhaust tell me that there is no reas

Discussion in 'Maintenance' started by JRNapalm, Sep 18, 2020.

  1. JRNapalm

    JRNapalm New Member

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    I'm asking because I took my bike to a mechanic that is usually very good, and I'm around the mileage where it should have the check done (15k miles on cbr 1000 rr 2011). When I went there he had a listen and put his hand to the exhaust and said along the lines of trust me there is no reason to check it or do anything with valves, but he do other things like changing oil, air filter and so on. Is this reasonable or not? Obviously I would like to not to pay money for something I don't need, but I also don't want my bike to run into issues
     
  2. Empty_Ten

    Empty_Ten New Member

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    I'm not mechanically minded so couldnt comment - but maybe its just experience having done other valve clearances at similar mileage?

    I just had mine done this year at 16k and the guy said all was fine and no adjustment needed. On my MT10's first valve clearance at 24k miles, I was also told they were fine and didnt need adjusting.

    I think there is a member here who has owned quite a few blades and ran them all to 30k+ miles and has never done a valve clearance on any of them with no issues.
     
  3. dern

    dern Active Member

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    Put his hand to the exhaust and be able to tell that the valve clearances don't need doing? Maybe the idea is that he's making it a bit quieter so he can hear the clatter of the valves or maybe he can't feel the bits of metal coming out yet so assumes it's fine ;)

    What he's probably trying to tell you is that it's unlikely that your valve clearances are out at 15k. If you've already got the airbox off to do the air filter you may as well lift the lid and check the valve clearances for the extra hour it'll take. Even if they're in spec he'll be able to record where they are in the range and he can make a judgement on when to do it next time.

    Mine weren't done until 22k and at that mileage they were outside spec on the exhaust side. Some are fine over 30k as has been said. How lucky do you feel?
     
  4. nigelrb

    nigelrb Elite Member

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    So do we have access to a 'bike whisperer' since my hiatus?:confused:
     
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  5. Blade runner 1

    Blade runner 1 Well-Known Member

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    If you’re not that bothered whether the valve clearances are within spec or not then take his advice. To make that statement he would have to be extremely familiar with the engine, even then the conclusion of his assessment only suggests that they are not noisy. Another consequence of incorrect valve clearance is the valve timing will be altered slightly. You may well have them checked and they will be absolutely fine, but it’s the only way to know for sure.
     
  6. Jez

    Jez Active Member

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    Welcome back nige, If you take your bike/car for valve check, chances are they will be done at a distance, If it does not bang and rattle it will not get checked .
     
  7. Cbrjay

    Cbrjay Well-Known Member

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    Ask him to warranty in writing that they are ok
     
  8. Jez

    Jez Active Member

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    Been down this avenue, paid for valve check ( this was on the car ), put tamper marks on the engine so I could tell if head etc had been disturbed, after the service nothing had been moved, the seals were still not broken. before I left the garage I told the manager the work had not been done, He said if my mechanic has ticked the box it has been done, I said come and have a look at my tamper seals they clearly show the work has not been done. He refused to look and just stuck with the line the work has been done
    I then got onto trading standards and told them and they said I would have to go back to the garage to complain as they were very busy.
    garage 1 customer 0 :mad:
     
  9. bonjo

    bonjo Active Member

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    I don't buy the mechanic's advice. How can he tell if any of the 16 (inlet & outlet) valves need or need not adjusting!
    When I had mine done back in Jan, the mechanic told me doing the job was extremely involved and tedious and you needed to know your way aroung the particular bike.
    I think this is the reason for Jez's experience.
    I would say the mechanic did not want to take the job on.
     
  10. CharlieR85

    CharlieR85 Senior Member

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    He obviously doesn't "know" whether they need adjusting or not but this approach is not uncommon. You can't let him do the work now, if you ask him to do it regardless he'll want to prove himself right.

    Go elsewhere if you want them checking.
     
    #10 CharlieR85, Sep 21, 2020
    Last edited: Sep 21, 2020
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  11. Selmer50mark

    Selmer50mark Elite Member

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    My RR7 has just about got to 16,000 miles ,,,,,,, think I'll do the check myself o_O
    Nice job for a wet weekend ;)
     
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  12. tuktuk

    tuktuk Elite Member

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    It's one of those jobs that for peace of mind is worth checking/ having checked.

    Bit annoying as anyone I know who has had it done on the blade hasn't needed any adjusting.
     
  13. stuart_g

    stuart_g Active Member

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    For the record your valves will not bang and clatter if they need adjusting. The valve clearance will get tighter as the valve seat wears and the valve sits deeper in the seat therefore closing the gap.
    If the valve seat wears excessively it will eventually lead to the valve not closing and will lose compression. This may be what the mechanic was listening for/trying to feel in the exhaust pressure as it will not be a smooth running engine.
    As said before the valve clearances being out of spec will slightly adjust the valve timing as it will be closer to the camshaft. For optimum running they should be checked and kept within spec.
    I would have them checked personally for peace of mind.
    Different bike i know but same principle, i just checked my KTM 350 valves and one inlet was at the tightest tolerance value so shim changed to get it back to being in the middle of the tolerance range. The other inlet and both exhaust valves were still in middle of range so you never know and can’t assume they are all ok.
     
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  14. Black & White

    Black & White New Member

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    This is absolutely correct. The camshaft does not wear out on its base circle because the cam follower doesn't touch it. The mechanic was feeling for any 'chuffing' that you might get if the valves aren't sealing/closing fully.
    As said, it's worth having them checked for peace of mind even though they are, apparently, rarely out of spec at 16k miles.
    Having said that, it's certainly not impossible that they are out of spec.
     

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