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Lazer Z and double blades???????

Discussion in 'Lawn Mowing' started by Fivestar, May 14, 2002.

  1. Fivestar

    Fivestar LawnSite Member
    Posts: 50

    I did a search on double blades and I didn`t see anyone mention anything about using longer spindle bolts when running D/B???
    What`s up with that? Do you or don`t you need to have longer spindle bolts to safely run D/Bs. Does anyone know what size threads Exmark uses on the Lazer 60 Z ? I would like to run D/Bs but if I do I want to make damn sure to do it right for saftey sake. Thanks for any input any of you may have.

    Fivestar: cool:
  2. SLS

    SLS LawnSite Bronze Member
    from Mars
    Posts: 1,540

    What year is your Lazer Z and how long are the bolts that are in it now?

    Earlier versions had a 'short' bolt (about 1.5" or so) and they had COURSE threads.

    The newer versions, about 2000 and later, have a longer bolt (3") and they have FINE threads.

    The later versions (3") are a 5/8 bolt with an 15/16 head. I BELIEVE the earlier (1.5") were also.

    The difference in the threads is what you have to look out for when changing to a longer bolt for running doubles.

    I hope this helps. :)
  3. Fivestar

    Fivestar LawnSite Member
    Posts: 50

    Thanks for the help SLS. I will check this out. But I wonder still about the spindle bolt length due to the fact that a second blade takes up about a 1/4 inch of the bolts thread. Correct me if I`m wrong.:blob4:
  4. SLS

    SLS LawnSite Bronze Member
    from Mars
    Posts: 1,540

    The 3' bolt is PLENTY long but if it is the 'shorter/course thead' type I would definately recommend finding longer bolts as 2 blades and the bellville washer take up about 3/4 of an inch of space. With sharp steel whirring around at 18,500 fps I feel that "better safe than sorry" is of utmost importance.

    One thing I do not know is if the older spindles have a deep enough threaded hole to accept a longer bolt. Maybe someone with an older Lazer will see this thread and respond if they know how deep the 'hole' is....or you could 'probe' it with a piece of wire, or a screwdriver, and do a measurement yourself. I have a 2001 Lazer so I didn't have to change anything...just a simple 'bolt 'em on' procedure. :)

    Remember too, that when using D/B's, to compensate for the loss of 1/4" cutting height when setting the cutting height lever.

    And proper balancing of the blades is important when running doubles. Keeps the spindles alive and the blades from trying to shift on ya.
  5. awm

    awm LawnSite Gold Member
    Posts: 3,354

    mine are the short . i still have plenty of threaded bolt in the spindle. one thing i have noticed is that after running doubles for a while it seemed the bolt didsnt want to go in far enough with singles.. guess theres a little build up in there or something.but it does hold fine.
    only problem w doubles u might need to be aware of is that if u hit something it sometimes jams certain type of blades togather ,to the point it takes an impact wrench to get it loose.
  6. TLS

    TLS LawnSite Fanatic
    Posts: 7,940

    Come on SLS, lets keep this "PG" rated here. None of this "probing deep holes" stuff :D :eek:

    Do this test....
    With your double blades on the bolt, thread the bolt into the spindle just till the threads start to catch. Now look at how much thread you still have! These are fine thread 5/8" bolts. If it was a through bolted design, they would have a 5/8" tall nut holding all of this together, so as long as you have more than 5/8" of threads left at this point, you'll be fine.

    I personally dont use doubles during the year on my 60" Lazer. I noticed too much blowout (grass all over my feet, in my boots, in my face) for it to be worth it. Plus even with my 27hp, I felt the engine works a bit too much for my liking with doubles. Add that to the 1/4" lower cut height in relation to the deck baffles and deck side skirt. I actually hit curbs and other things with the blade almost protruding lower than the deck skirt.

    Try the NEW fully sharpened, solid foil, highlift EXCALIBURS from Exmark (About $11 each).
  7. Fivestar

    Fivestar LawnSite Member
    Posts: 50

    Thank you guys for the info. Very helpful. Thank God for Lawnsite
    its the best!! Keep on truckin or should I say keep on with the strippin!! :cool: :cool: :cool:


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