Author 2019 850 - No compression  (Read 810 times)

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  • Offline Day-tony   us

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      #10

    Offline Day-tony

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    Re: 2019 850 - No compression
    Reply #10 on: Jan 19, 2023, 07.50 am
    Jan 19, 2023, 07.50 am
    Better photo with exhaust cam lined up parallel to mating surface. Inlet cam appears to be about two teeth off.


  • Online SnoDrtRider   us

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      #11

    Online SnoDrtRider

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    Re: 2019 850 - No compression
    Reply #11 on: Jan 19, 2023, 01.34 pm
    Jan 19, 2023, 01.34 pm
    You need to check to see if the crankshaft is at TDC in order to know if the timing marks are in the correct position.


  • Offline MCMXCIVRS   ca

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      #12

    Offline MCMXCIVRS

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    Re: 2019 850 - No compression
    Reply #12 on: Jan 19, 2023, 04.16 pm
    Jan 19, 2023, 04.16 pm
    From the pics, it does appear that the chain could have jumped a few teeth but hard to be certain without knowing where the crank is positioned. As for the crossover of the leakdown test, you need to be sure the valves of the cylinder being tested are fully closed. If the valve is open (or bent and not seating), it is possible that the air flow is backtracking through the intake and or exhaust to get to the other cylinder.

    At any rate, it looks like some level of teardown is in your future with this bike. I'd suggest pulling the cams out so the valves can be verified as closed then redo the leakdown and see what results you get. If everything is holding at that point, then reassembly with a new chain and corrected cam timing will hopefully sort the problem. If not, then you'll be going further into the engine with head removal at least.

  • Offline MitzaPCH   ro

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    Offline MitzaPCH

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    Re: 2019 850 - No compression
    Reply #13 on: Jan 21, 2023, 06.58 pm
    Jan 21, 2023, 06.58 pm
    Cam chain tensioner needs to be changed, mine was like that aswell, changed it and is way better now.

  • Offline Day-tony   us

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    Offline Day-tony

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    Re: 2019 850 - No compression
    Reply #14 on: Jan 21, 2023, 07.19 pm
    Jan 21, 2023, 07.19 pm
    *Originally Posted by MitzaPCH [+]
    Cam chain tensioner needs to be changed, mine was like that aswell, changed it and is way better now.

    I think so too, but how could you tell it was bad? Did you do the oil bath? Did you switch to the manual tensioner? I'm thinking when I get the valves/timing chain/compression sorted I will go the manual tensioner route.

  • Offline Day-tony   us

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    Offline Day-tony

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    Re: 2019 850 - No compression
    Reply #15 on: Feb 02, 2023, 11.17 pm
    Feb 02, 2023, 11.17 pm
    *Originally Posted by MitzaPCH [+]
    Cam chain tensioner needs to be changed, mine was like that aswell, changed it and is way better now.

    Hi MitzaPCH. Are you able to elaborate? Did yours actually jump teeth/timing due to the faulty chain tensioner? Did any damage to valves, etc. occur? What all did you have to do to fix? Thanks for chiming in.