Kawasaki FB460V Compression Release

Discussion in 'Mechanic and Repair' started by firefightercfd, Aug 12, 2008.

  1. firefightercfd

    firefightercfd LawnSite Member
    Posts: 7

    I have got a problem with my Exmark Metro 36" with the 12.5 Kawasaki FB460V engine. When I purchased the mower used, it would start with no problem. Just choke it and pull. Now the mower takes 20 - 30 pulls before it starts. I have read all the other threads on this issue, but none of them seem to answer my questions.

    We took the head off tonight to check the valves. Both valves look fine and both appear to be seating fine. We did notice that the exhaust valve opens 0.030 during the compression stroke. Is this due to the Compression Release? Also during starting, there is a "ting" sound coming from the engine block in the area of the camshaft.

    When the engine is finally started, it runs great. But when I shut it off, 20-30 pulls. Hot or cold it does not matter.

    It does appear that the butterfly valve does not close completely at the choke setting. I will need to adjust this in the morning.

    I have written everything that I can think of at this time. I hope that someone can help me.

    Thanks
    Kevin

    Jones Lawn Services
     
  2. FIXDISS

    FIXDISS LawnSite Senior Member
    Posts: 445

    BINGO ! Choke must be fully closed to start even when engine is at operating temperature. The "tink" sound you hear when rotating engine is the compression release engaging.
     
  3. firefightercfd

    firefightercfd LawnSite Member
    Posts: 7

    Thanks for the quick reply. I will adjust the choke first thing in the AM and see what happens. I really did not want to break open the block and find nothing wrong.

    Kevin
     
  4. FIXDISS

    FIXDISS LawnSite Senior Member
    Posts: 445

    If you got this unit used do you have any idea when valves have been adjusted ? Kaw reccomends every 300 hrs so I have read here .
     
  5. firefightercfd

    firefightercfd LawnSite Member
    Posts: 7

    When I bought it, I was told that it had about 25 hrs on it and was used residentially. I have only used it for one season on about 10 lawns a week. Don't think that I am at 300 hrs yet.

    Kevin
     
  6. Jay Ray

    Jay Ray LawnSite Fanatic
    Posts: 6,510

    This assumes your choke is fully closing and is not the problem.

    If you got a fuel shut-off valve close it. Then drain the bowl & close it back up. Remove spark plug and pull a few times to clear the chamber of possible flooding. Clean & replace plug. Remove air filter, spray starting fluid or gas into the carb. If it happens to start easy I would suspect a faulty needle valve or its seat (or both).

    But this is only an unprofessional, shadetree guess.

    i have 2 FB460V's and have been thru the choke problem on one of them. Have had the flooding problem on other engines.
     
  7. firefightercfd

    firefightercfd LawnSite Member
    Posts: 7

    Solved the problem. Intake valve was not seated properly. There was no clearance between the valve and the tappet. Valve clearance set and the the valve lapped. Starts on the first pull.

    FixDiss - The butterfly was closing all the way.

    Thanks all for the help

    Kevin
     

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