My NEW eXmark Lazer Z X-Series with RED technology

Discussion in 'Lawn Mowing Equipment' started by TLS, May 11, 2013.

  1. puppypaws

    puppypaws LawnSite Fanatic
    Posts: 8,906

    You must be in extremely heavy, wet, cutting, but I'm still surprised you hear very much change. You and I both know you can take grass loaded with moisture and it will pull an engine harder than dry grass twice the size. The E-Governor senses load and adjust fuel accordingly, this is why you are not suppose to get the extreme change which affects the sound of lowering and raising engine speed. As you well know, anytime you hear the engine raise and lower speed, fuel economy is being affected.

    I am really quite surprised you noticed a great deal of change in sound, but with fuel numbers on a new engine at 1.3 gph in heavy cutting, there is nothing terribly wrong.

    This is an area Generac has excelled in for many years with their engines. They implemented the E-Governor on their generator engines years ago so as additional power is needed the engine could have more fuel added to compensate and prevent rpm lag, this way there would be no drop in amperage from the generator output.
     
  2. TLS

    TLS LawnSite Fanatic
    Posts: 7,940

    Puppy, Like you said its extreme conditions. These are conditions that would bring my 28 EFI to its knees.
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  3. puppypaws

    puppypaws LawnSite Fanatic
    Posts: 8,906

    I would say it is probably conditions you could stall the 28 efi stone cold dead. I've cut areas this year due to extremely large wet grass that I just change mowers and moved over to the 35/72 to make the job less straining on the mower, but I still love the 28 efi in most all my cutting situations. The engine has ample hp in normal cutting, and the fuel economy for engine size is exceptional.

    When I find the need to get the cutting done in a hurry, the 35/72 will make it happen, it honestly amazes me to look back and see how much grass I've cut in the past 15 minutes, it would be mind boggling for most anyone cutting grass for a living to watch.
     
  4. TLS

    TLS LawnSite Fanatic
    Posts: 7,940

    Put it through it's paces today again. This should be the last of the long ones!

    I was mowing a bi-weekly multi-acre future sub-division building lot. The grass was caster arm height. It took this from that height down to 4" without breaking a sweat -- Power wise. That's the good news -- Plenty of power.

    Bad news...I forgot how bad UC decks are at mowing TALL grass! It required a second pass to get it smooth. This is where an open front deck would do much better. It didn't bog, load up or anything real bad. It just motored through it and would go through it full stick if I wanted it to!

    I put another 7hrs on it today so sometime tomorrow I'll fill up and check the Gal/hr again. The tankful after that should be much more normal cutting, as I'll be hitting lawns at 6 days growth.
     
  5. puppypaws

    puppypaws LawnSite Fanatic
    Posts: 8,906

    Good to know, looking forward to the fuel numbers...
     
  6. TLS

    TLS LawnSite Fanatic
    Posts: 7,940

    Last two tankfuls :

    1.38 g/hr

    And

    1.23 g/hr

    I'm impressed! Still find it hard to switch to efficiency mode, as I'm so used to HAVING to maintain full throttle on the SuperZ.

    By the way. This blows away the g/hr I was getting with the SuperZ. That engine just had to work so hard all the time. This big block just loafs around and laughs at hills and tall grass!
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  7. puppypaws

    puppypaws LawnSite Fanatic
    Posts: 8,906

    This is one reason I've always contended it's better to have too much power than not enough. What you've just stated is a perfect example of this. When you get into summer cutting with everything somewhat dryer and not growing as quickly due to hot weather, I would say this engine will cut everything with such ease you will see the fuel usage drop even lower, but year end and year out, I'm still sticking with a 1.25 gph avg.

    The area of the country I live in makes a tremendous difference in how grass cuts. We are already getting high 80 and low 90° weather, which when cutting on a tight schedule such as I do, my 28 efi has no problems.

    I cut a waterway yesterday that had only been cut (and very high) once this year due to wet weather, I knew to take the 72/35, and it handled it with no problem, whereas if I used the 28 it would have worked it to death. Now, to go in the opposite direction, the 28 efi handled everything outside the waterway with no problem. Cutting grass is relative to the conditions, with dryer conditions on a 6 day schedule being very conducive to the lower fuel usage and power of the 28 efi, go in the opposite direction and the big block is my engine of choice.

    I'm pulling a 72" deck with only very little more power than you are pulling a 60" deck, your mower should basically never need to work hard at all. I know your 34 would check at a lesser actual hp, but with fuel injection, I'm betting it's back to a closer 34 range, probably around 32 to 33 actual hp. This, and the responsiveness due to fuel injection and the E-Governor should keep you from finding a need for additional hp, your engine should by all rights be a horse, and one that requires very little feed and water.

    I'm wondering how much the efficiency mode drops the rpm's, the hydraulics on these mowers are designed for best cooling efficiency at their rated rpm, which is normally 3600. This makes me wonder if lowering rpm's such as in the efficiency mode will cause the hydraulics to run hotter due to fan speed being slowed.
     
    Last edited: May 17, 2013
  8. TLS

    TLS LawnSite Fanatic
    Posts: 7,940

    Just put a Tiny-Tach on it last night. I'll let you know.
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  9. TLS

    TLS LawnSite Fanatic
    Posts: 7,940

    When this RED/E-Gov becomes common on all engines. I could see 800cc's being perfect for most ZTR's. Hell, if our little 725 EFI's did what they do, 800's should be perfect. No need for the 1 Liter class.
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  10. mtmower

    mtmower LawnSite Bronze Member
    Posts: 1,115

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