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  1. #1

    Join Date
    Apr 2011
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    compression test help

    rebuilt the engine new rings (in correct position) took the head off to change a valve now compression is at 30 across all 3 cylinders please help i suspect timing but im using the 4 timing tools and compression isnt anywhere close what i need

    what happened was i had a damaged exhaust valve (no damage to engine or any other parts) so i removed the head to change the valve while i was doing this i didnt put any marks on the engine to reuse when it was time to reassemble seeing that i had the crank locking and cam locking tools after reassembling the engine did a compression test seeing thats the first to do and got 30 psi on all 3 please help


  2. #2
    Depth's Avatar
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    Oct 2012
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    North QLD, Australia
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    If you've got new rings and bores you won't get peak compression numbers until the rings have bedded in after run in but 30 psi sounds real low I'd double check and triple check the timing as per the manual you don't wanna start it with the timing out

  3. #3
    Eastside Powersports Slow 91's Avatar
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    did you hone the block? or just install new rings on the old bore?

  4. #4

    Join Date
    Apr 2011
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    grand cayman
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    New hone and yeah timing is my number one suspect but I don't know if its right I used the cam locking and crank locking tools at the same time when doing the timing or just asking is it number one next to timming chain that needs to me tdc when using the cam locking tool or is it number 3 farthes away from the timing chain or closest to the front of the ski that needs to be tdc

  5. #5
    Got Boost? psycho rxp's Avatar
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    #3 closest to gas tank should be at TDC

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