Anonymous
Anonymous asked in Cars & TransportationMotorcycles · 6 months ago

Hi what does it mean if I have low compression on my pit bike ?

13 Answers

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  • 6 months ago

    depends on the ACTUAL pit bike. Is it a 4 stroke or 2 stroke? OHC or OHV as many Chinese Honda clones use? OHV clone small engine used in lawnmowers known to have intake/exhaust valves set close so don't rattle much- but with some running a bit of wear means zero lash cold turns to .002 to 004 negative clearance warm- solution is remove calve cover held with 1 or sometimes 2 cap screws or big wing nut and adjust valve lash to .004/.006 cold - get some rattle on start and maybe 3 minutes to warm up will still have a very slight tick when warm- and no leakage. For some engines the valve lash setting means pull pushrod and grind end, others used to have to remove valve and grind down end of valve stem- this for the early Brigges and Tecumsehs L heads. Couple incidents of head bolts not getting retorqued after few hours running, loosened bolt or cap screw means head gasket not sealed and leak results, later burned through gasket. Replace head gasket after cleaning surface of head and cylinder. @ strokes? check exhaust port for fouling, spark arrestor fouled.

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  • zipper
    Lv 6
    6 months ago

    COULD be bad rings, or burnt values, sounds like over hall time!

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  • 6 months ago

    It means that there is not a tight seal between the piston and cylinder. This is a very serious problem because you will lack power and burn oil.

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  • adam
    Lv 4
    6 months ago

    I never do compression test. Do a cylinder leak down test instead It will give you a better idea of whats going on

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  • Anonymous
    6 months ago

    It will run like a gutless wonder.

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  • 6 months ago

    Test it again but this time hold the throttle WIDE open. I bet you get a much better result.

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  • 6 months ago

    Needs new rings, a cylinder bore, or possibly a head rebuild.

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  • 6 months ago

    It means you need to overhaul the engine.

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  • Tim D
    Lv 7
    6 months ago

    Possibly that your rings are not forming as tight as a fit as they should, so as the piston raises some of the gases are escaping past the rings rather than being compressed. There are other possibilities, only investigation will reveal the problem.

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  • Anonymous
    6 months ago

    It needs a rebore with an oversized piston and rings fitted.

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