replacing valves

Discussion in 'Mechanic and Repair' started by Scenic Lawnscape, Jun 29, 2004.

  1. Scenic Lawnscape

    Scenic Lawnscape LawnSite Senior Member
    Messages: 288

    what is the trick to replacing valves on a kohler magnum 20, i had a screw get sucked in to the intake and i had to replace the piston and head, now i noticed that the exhaust valve isnt seating, so i need to replace it. How hard and how do i do it??


  2. Itsgottobegreen

    Itsgottobegreen LawnSite Silver Member
    Messages: 2,177

    Is hard if you don't have the tools. If the seat isn't to bad its an easy fix. If not see a small engine shop (trust me its easier)

    1st get a briggs and straton valve compressor, lapping tools, valve grinding compound. misc hand tools.

    Use the valve compressor to compress the valve, then lift up the spring, while holding the valve down. Two little pieces should fall off the valve's shaft. The two pieces are the retaining clips (don't lose them) Then pull the valve out Remove the valve spring. If the seat has visible marks in it. See the engine shop, they have the seat cutters needed to fix it. If there are no marks. Take the valve grinding compound and apply it to the new valve around the angled surface. Place valve back into the hole. Take the lapping tool, stick it to the valve. Roll the tool back and forth in your hand, while applying some down pressure. Do this until the grinding sound stops (2 to 4 seconds) Put the valve up slightly, turn 45 degrees and repeat the process. Do this about 6 to 8 times. Clean off all surfaces. Or the grind compound will destroy the engine in 5 to 10 mins. Replace valve spring (keep it on the compressor), insert the valve, put the two retain clips back on the valve's shaft, (a little grease on the inside of them help to keep them in place) Release the valve compressor. Rotate the engine to see if valve still is function properly. If its not making a complete seal. Call kohler to get the spec on the space between the end of the valve to the push rod. Adjust the spacing and you should be ready to go.

    Its easier than it sounds. I have done it a bunch of times.

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