Discussion in 'Mechanic and Repair' started by GSPHUNTER, Mar 2, 2008.


    GSPHUNTER LawnSite Senior Member
    Posts: 310

    I've pretty well got my mind made up, but I guess I need to write this any way. My buddy is getting out of the biz this year and he's trying to sell his
    52" Ferris to me.

    I ran a comp. test on a 23 hp Kaw engine and got 120 from cylinder 1 and 90 from cylinder 2. Needless to say, this was alarming. Anybody have any ideas of quick fixes that could be causing this?:hammerhead:
  2. newz7151

    newz7151 LawnSite Silver Member
    from Tejas
    Posts: 2,419

    HG on CYL2 ?
  3. Jason Pallas

    Jason Pallas LawnSite Bronze Member
    Posts: 1,325

    That's certainly a possibility.

    GSPHUNTER LawnSite Senior Member
    Posts: 310

    HG = Head Gasket? I'm assuming that if this is the problem, it is a pain to fix and not worth buying a headache.
  5. newz7151

    newz7151 LawnSite Silver Member
    from Tejas
    Posts: 2,419

    Depends on what caused the HG to malfunction.
  6. MowerMedic77

    MowerMedic77 LawnSite Bronze Member
    Posts: 1,164

    Are you performing this compression test with the engine cold or after it has had time to get to operating temp?

    GSPHUNTER LawnSite Senior Member
    Posts: 310

    I did it cold real quick last night, and I know it is supposed to be at operating temp. I'll test it again tonight after it's warmed up, but do you really think it's going to make a 30psi difference in compression after it's warm. Also, the mower had been running about 5 hrs before I did the test, so oil should have still been on the cylinder wall I would think.

    Thanks for the replies.
  8. shepoutside

    shepoutside LawnSite Bronze Member
    Posts: 1,205

    If it is less than expected, squirt a small amount of engine oil in through the spark plug hole so it coats all around the edge of the piston and cylinder.

    Repeat the compression test.

    If the pressure reading is now acceptable, then the rings need replacement or the piston/cylinder are excessively worn. If there is little change, there is a valve problem.

    If the measurement is very low under both conditions, there may be a blown head gasket or damaged (punctured) cylinder or head. (Or your engine has a compression release mechanism which is reducing the reading)
  9. CarterKraft

    CarterKraft LawnSite Senior Member
    Posts: 290

    just a guess but doesn't that engine have a low RPM compression release on the cam?

    If so that would bleed the cylinder pressure off giving a false reading?

    Just a thought, I haven't worked on air cooled in a long time.

    GSPHUNTER LawnSite Senior Member
    Posts: 310

    Well, I went out last night and fired it up for about 5 minutes. Tested the low cylinder first this time and it read 110 psi. Then I tested the other cylinder and it read 130 psi, so I closed the variance a little between cylinders. That still seems like a pretty high difference though.

    Also, this is a 2004 Kawasaki with approximately 1000-1200 hours on it.


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