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compresion check on 17 Kaw.??

Discussion in 'Mechanic and Repair' started by DEA, Sep 3, 2004.

  1. DEA

    DEA LawnSite Member
    Posts: 55

    When doing a compression check on a Kawasaki 17 horse. twin.
    Sould you ground the spark plugs or no ground them when cranking the engine over??
    I'm getting a used wb and this is one of the thing I was goin to check
  2. fixer67

    fixer67 LawnSite Silver Member
    Posts: 2,100

    Compression check has nothing to do with grounding the spark plugs. The only reason to do so is a matter of safety. If there is fuel or fuel vapor and one of the plugs does spark wires does spark against the frame you could have a flash fire. By grounding the plug wires you prevent any spark that may cause such an event. It is a million to 1 long shot you could get it to do it if you wanted to. Grounding or not grounding will not change yor readings. Now there is a problem with doing Compression check on Kawasaki engines and some like them. There is a Compression release built in to lower Compression on start up and you will get a low reading or even no reading. You need to do a Leak-down test instead. This will give you a better reading. You will need a speical gauge set up to do this test. How it works is you rotate the pistion to Top Dead Center on the Compression stroke and pressurize the cylinder though the spark pulg hole with 100 PSI and the gauge tells you how much blow by ( from rings and valves and head gaskets) you have in a % reading.
  3. Four C. Landscaping

    Four C. Landscaping LawnSite Member
    Posts: 76

    Gas vapors can linger in the cylinder for a wile so make sure the plug is away from the plug hole before you even consider turning the engine over BECAUSE gas explosions are bad bad bad.Secondly grounding the plug will make no diffrence on the compression test.Good luck!
  4. DEA

    DEA LawnSite Member
    Posts: 55

    The reason I was wondering of werether or not to ground the plugs was to prevent damage to the electronic ingition system.
    When I worked in the motorcycle field there were some motorcycles that you could not ground out doing damage to the CDI system

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