"Souped Up" Kohler 27hp ??

Discussion in 'Lawn Mowing' started by cajuncreole, Feb 28, 2008.

  1. cajuncreole

    cajuncreole LawnSite Member
    Messages: 34

    I have an Exmark 66" 27hp Kohler. I mow in South Louisiana and have quite a few old pastures to keep up 5-10 acres. They are in Bahaia some on former garden plots, so the grass is very thick.

    I mow most once a week, but some every other week and during the spring on certain very thick parts of the plots with the throttle wide open, the Kohler 'boggs down" and I have to crawl through the area, to keep from stalling the engine out.

    I went to the mechanic at the dealer, he is a very competent mechanic, and he said he would "advance the spring setting on the governor" and I should be able to get through this heavy grass without slowing down as much.

    He said he would install a tach on the mower and I should never go over Kohlers recommended top end of 3600 RPM's.

    I sharpen the blades daily, clean the deck daily and spray it with lube to keep grass from building up. I run synthetic oil and change filters as needed. Any thoughts??

  2. topsites

    topsites LawnSite Fanatic
    Messages: 21,652

    All depends how long you been doing this, I think.

    Because I did that for a while, until I got tired of it.

    Now I do all that and run a namebrand premium unleaded, plus autolite double platinum plugs (keep in mind they need replacing every 2 seasons vs. every 1 for standard), autolite.com offers a cross-reference thing on their site.

    But once it gets to a point my machine starts to bog down anyhow we have a problem, because it shouldn't.
    Yes sir, sharp blades daily and a clean pre-cleaner and all that crap, come on now.
    So either I can come by more often, I can charge extra, or my best solution yet is I start to raise the cut height.

    This works for most, most of the time.

    But one way or another, push comes to shove like I show up and I can see it needs it now and the customer comes running out talk about wait another 3 days (or better yet another week)? No problem, I get back in my truck, and leave. When they call wondering where I am, I'll be there tomorrow.
  3. Richard Martin

    Richard Martin LawnSite Fanatic
    Messages: 14,698

    I don't recommend adjust the governor spring. If it's weak and needs to be replaced then fine, replace it. Otherwise leave it alone. The governor spring is set to control engine RPM. It is also set to control surging too which is usually the result when you try to adjust it.

    Unfortunately 27 HP is 27 HP and there is no quick or safe way to increase it. Your only recourse is to cut it more often or raise the height of cut.

    You can also raise the RPM to 3750 but watch for increased oil consumption.
  4. MarcSmith

    MarcSmith LawnSite Fanatic
    Messages: 7,157

    gotta remember the mower is a finish mower, and not a bush hog.... you either have to cut more frequently or cut higher . The only other thing you could possibly do would be to "re pully" the spindles, to get a higher blade tip speed, or put on a heavier blade that way once the heavier mass gets spinning its harder to slow down...

    you you do a double cut, cut it once high, and then drop it down for the second cut....but then they better be paying for the double cut.
  5. cajuncreole

    cajuncreole LawnSite Member
    Messages: 34

    Thanks guys, so to maximize engine efficiency horse power:
    1) Sharpen blades daily.
    2) Clean deck underside daily.
    3) Spray deck underside with lube.
    4) Premium gas.
    5) Premium plugs.
    6) Synthetic oil.
    7) Clean filters.
    8) Repulley spindles for higher Blade Tip Speed.
    9) Advance governor for higher RPM's to 3750.

    Anyother tips on what works for you. I have to get the most out of what I have.
  6. tb8100

    tb8100 LawnSite Bronze Member
    from TX
    Messages: 1,625

    Air precleaner and filterminder gauge to monitor restriction.
  7. puppypaws

    puppypaws LawnSite Fanatic
    Messages: 9,179

    Mistake.... Kohler's recommended rpm's on the 27 hp is 3750.... some use more oil, some don't!
  8. Richard Martin

    Richard Martin LawnSite Fanatic
    Messages: 14,698

    I don't like this one. Although you can increase the BTS this way it also decreases the torque going to the blades. Torque is twisting force. If you hit a heavy patch of grass the engine will have to work harder and will probably loose RPM faster. Just increase the engine RPM as this will increase BTS anyway. You do not have to touch the governor or the spring to do this. There is a simple adjustment bolt on the throttle linkage designed just for adjusting the top end RPM. You may need to also adjust the throttle cable too.
  9. delphied

    delphied LawnSite Silver Member
    Messages: 2,067

    Your last sentence goes against numbers 6, 8 , and 9. According to my Kohler manual, synthetic oil is not recommended. As for 8 & 9, reengineering the mower is, IMHO going to get you the least out of what you have in the long run. If that needs an explanation then all hope is lost anyway. Your best advice in this thread was that you have a finnish mower, not a bush hog and that you need to mow when it needs to be mowed or dont take the job. As for the rest of the items on that list, they should be done with any mower regardless of the conditions of mowing.
  10. tb8100

    tb8100 LawnSite Bronze Member
    from TX
    Messages: 1,625

    of course synthetic is not recommended! They want you to buy more engines from them!

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