engine rpm's

Discussion in 'Lawn Mowing' started by timmac, Sep 12, 2007.

  1. timmac

    timmac LawnSite Senior Member
    Messages: 480

    how do you adjust the engine rpm's on a hustler super z 27? I put some high lift blades on the mower and it is losing alot of power and bogging down when I mow and I am having to go real slow. I just figure the rpm's need to be adjusted.
  2. joshco84

    joshco84 LawnSite Senior Member
    Messages: 411

    clean out the air filter probably. and instead of cleaning out, pull it out and put a new one in. this would be my guess.
  3. tacoma200

    tacoma200 LawnSite Fanatic
    Messages: 5,426

    Well if you adjust the rpm's above the factory reccomended setting it may void the warranty, plus it will give you little if any extra power. A Super Z is underpowered at best in my opinion and there's not much you can do but to go slower to keep the rpm's up. Those big pumps, motors, put a strain on the limited hp of the vertical engine options, add high lifts and it's just that much more of a strain on the engine. Those Super Z's are such a comfortable mower its a shame they are limited by the hp of a vertical engine but that may change soon with some of the larger hp engines coming out.
  4. Mickhippy

    Mickhippy LawnSite Platinum Member
    Messages: 4,274

    I had my mechanic up the revs on my SZ 28efi to 3750 rpm. Made a massive difference for me. Should of done it last season.
  5. lawnspecialties

    lawnspecialties LawnSite Silver Member
    Messages: 2,524

    If you have the Donaldson canister system, throw the inner filter out and don't replace (per Hustler and my dealer).
  6. dave k

    dave k LawnSite Bronze Member
    Messages: 1,177

    Would that go for a Walker as well? taking the middle air filter out?
  7. joshco84

    joshco84 LawnSite Senior Member
    Messages: 411

    you really want that inner air filter in there. they are designed with two filters for a reason. If your dealer told you to do that they are idiots. Sometimes the outer filter will get plugged and suck stuff through and you will wish you had left that inner fillter in. Especially when you are writing that big check for a new motor.
  8. tacoma200

    tacoma200 LawnSite Fanatic
    Messages: 5,426

    I agree, that's the whole reason they are going to the double filter to protect the engine and give you more time between service. As dusty as it gets mowing you need all the protection you can get. Most engines are set at the factory to run about the max rpm recommended (about 3700-3750 rpm) depending on model, brand etc. I wouldn't go over the max recommended.
  9. puppypaws

    puppypaws LawnSite Fanatic
    Messages: 9,164

    When I jacked my 28 efi up to 3750 it started using oil, dropped it back to 3700 and it stopped. I can't understand how 50 rpm's could cause this difference, saw the same thing posted by other people. The engine I have just doesn't use any oil at all to speak of, I may add 12 oz's in 50 hrs.

    You can definitely tell a difference in 3600 and 3750 in the operation of the mower.
  10. puppypaws

    puppypaws LawnSite Fanatic
    Messages: 9,164

    Push the throttle to full open with no load, loosen the throttle cable clamp and pull the cable until you hear the rpm's raise slightly, snug the clamp and check the rpm's. Set them where you are satisfied and tighten the throttle cable clamp tight enough so it cannot move.

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