Tri-Vantage deck & clumping GETTING AGITATED

Discussion in 'eXmark' started by Navig8r, Aug 16, 2003.

  1. Navig8r

    Navig8r LawnSite Senior Member
    Posts: 477

    I have a 2002 Lazer Z HP, 23 Kawi, 52"
    On good lawns.... it cuts better than I could ever hope for.

    I have found that, as many others have commented, it clumps badly in wet, or heavy growth.
    I have tried different blades / combos / doubles combos.
    It seems that the clumping is MUCH worse if there are any weeds or crabgrass in the lawn. "Clean" Lawns with little weed growth seem to cut fine in almost all conditions, except tall & wet, which I can understand.

    The problem I have is that I get A LOT of clumping on some lawns (with weed content) even in DRY, REGULAR GROWTH conditions!
    I use Mo-Deck on the deck, but at $8.00/can... it gets a little pricey.

    When a lawn is tall, I use my 8 yr. old SCAG 14HP WB,.... it cuts better, and disperses clippings better.... WHY???
    That's hard to swallow when I think about what I paid for my eXmark..... really gets me MAD!
    I met another LCO yesterday who asked me "I see you have an Exmark on your trailer..... WHY?!?!?"
    He had bought one and brought it back to the dealer 2 weeks later for a different machine..... Why?..... CLUMPING !!!

    It seems that lift of the blades actually contributes to the clumping, because when I throttle down, or disengage the blades, the deck will drop a HUGE load of clippings right there in one big mess as the blades "spin down"........ really inconvenient if I need to disengage in the middle of a lawn to move an obstruction, etc..... leaves a mess in the lawn for me to clean up........

    Would low-lift blades work better in TALL or WET growth??
    Anybody ever tried anything different?
    Any other suggestions from the eXmark camp????

    Would appreciate any help with this... I'm gettin tired of double cutting because my $7500 mower decided to blast 5 lbs of clippings out on every-other pass.

    Thanks for any help.
     
  2. TLS

    TLS LawnSite Fanatic
    Posts: 7,937

    Two words.....

    CRABGRASS

    and

    SUMMER WEEDS

    Mix them with the EXTREMELY WET summer we're having and you have yourself a nightmare for a mower deck.

    The crabgrass will ALWAYS be wet. Even in the middle of a 100 degree, sunny day, it'll come out in big wet clumps. This happens on ALL mowers. This has been a very odd year for growth and conditions, and I believe EVERY deck is experiencing problems like you describe.

    The Exmark decks do have front baffles in them that take each chambers clippings and send them into the middle of the next blades chamber, and so on. Some decks DON'T have this, and quit possibly may not experience this condition to your extent. Your 8 YO SCAG is an example of a baffle-less deck. I cant stand how bad my SCAG like yours cuts. No comparison in my book, but you may be right on these odd conditions that they "may" clump less because each blade only cuts the grass once.

    Things I would check though.....Deck pitch, blade sharpness, and engine RPM.

    I don't beleive its your mower, because you said it cuts FINE on "nicer" lawns.
     
  3. BigDave

    BigDave LawnSite Member
    Posts: 148

    TLS,

    That is a very interesting observation you make about crabgrass holding moisture. I never made that connection, but now that I think about it ... that might be the reason I'm slipping and sliding around so much this season.

    I'm going to post a msg on the Commercial forum for other comments on this subject.
     
  4. eXmark

    eXmark Manufacturer / Sponsor
    Posts: 4,258

    Navig8r,

    TLS is right on the money with his recommendations. I'll assume your still side discharging


    There are a few things that should be checked. First if you want my opinion I'd chuck any ideas of running doubles or any blades with serrated airfoils in your part of the country right now.

    On the Lazer HP you'll want to check the deck idler to ensure that it's pivoting freely. If it's plugging as badly as you've described it'll be worth your time to unbolt the idler arm from the deck, clean the pivot bushing surfaces with emery cloth and reinstall. Next you'll want to get the mower into the dealer and have the engine rpm check, as well as the deck rake. What is the rake now? You can also have your dealer call me when he has it in the shop. That way I can walk him through the inspection as well as setting the rake. The key is to find out what the deck is at now.

    Second go with the "notched" airfoil blade (STD equipment when new). The solid airfoil should plug the deck quickly and the low lift will keep the deck clean but it may not cut cleanly.

    Any deck will plug with the weather the east coast has been having. Increasing your ground speed will actually help keep the deck a little cleaner. I call it the garbage in garbage out theory. The new clippings simply help push the already cut clippings out the discharge rather than letting them stick to the roof.

    Use the force. When the deck begins to fill you'll hear it with your ears but you'll also feel it in your feet, seat and hands. As the deck fills with grass the tone of the deck will change significantly. You can also feel it in your feet, seat and hands as small clumps of clippings fall from the roof and make contact with the blades you'll feel a small vibration. When that begins to happen you can either increase your ground speed or throttle down and them back up. By throttling down you allow gravity to over power the lift and allows the deck to partially "clean" itself with out dumping. Since the blades are still spinning the clippings don't tend to pile up as badly as they would if you shut the PTO off.

    Also don't turn the PTO off until you've throttled down. This again not only helps to disperse the clippings but dramatically improves the life of the clutch.

    Let me know what you find out on the deck pitch/rake.

    Thanks

    Terry
     
  5. Navig8r

    Navig8r LawnSite Senior Member
    Posts: 477

    Terry and Tommy... thanks!

    I appreciate the quick response, and you've given me some things to look at......

    Terry, I have been running notched hi-lifts, I don't own any solid foil, or low-lift blades, so I hadn't tried them.......... I get the same amount of clumps with the doubles, but I find that the doubles scatter the clumps better.

    What should my full throttle engine speed be, in RPM's?

    The deck idler is operating smoothly, I removed the belt and worked the idler back & forth when I last greased the machine (less than 20 hrs ago) The total hours on the machine is only 150.

    I currently do not have the time to get the machine to my dealer unless something major came up, and I would like to CHECK the rake of the deck myself.......
    I have access to a flat, level floor. Do I measure the front height at the "point" of the deck in front of the center blade?, or elsewhere?

    It is my understanding that 1/4" lower in front is best. is this true?

    One more ??? (un-related to clumping) You mentioned throttling down before dis-engaging the clutch in order to reduce wear. I usually do that anyway, but how does that reduce wear? The clutch does not seem to act as a "brake" for the blades. I thought the system "free-wheeled" when dis-engaged. Obviously I am wrong, as you would know better.

    I DO engage the blades at a reduced RPM, then throttle up to full.


    Thanks again for the help. Its great that we can have a discussion about these machines, without being given only the "textbook" answers, but actually addressing real-world situations.
     
  6. TLS

    TLS LawnSite Fanatic
    Posts: 7,937

    Some quick help....

    Engine RPM's should be 3750 free of load. Blades NOT on, mower sitting still.

    Your blade clutch is a BRAKE as well. There are detailed procedures in the owners manual that outline its part in the mowers overall safety. If your blades simply freewheel to a stop (more than 2 seconds) you have a problem.

    May want to stop using Mo-Deck, I've never used it and cant see it helping in these conditions.

    The deck pitch should be between 1/8" an 1/4" lower at the FRONT tips of the blades than the REAR tips of the blades. Go to your dealer and buy one of these that I pictured. It will make checking a cinch.

    I'll assume your notched foil blades are the Excalibur then (full length sharpened)? If not, get them, and get them sharpened and balanced. They are a great blade, but no blade is any good if its slightly dull and unbalanced.


    I also like the free exchange of knowledge that eXmark provides. All too often I'm glad that we are not hearing "See your local authorized eXmark dealer" when we ask a detailed question.

    Good Luck!

    blade height tool.jpg
     
  7. eXmark

    eXmark Manufacturer / Sponsor
    Posts: 4,258

    Nav,

    The engine should be set at 3600 with the blades engaged but not cutting.

    Normally your deck should have about 1/4" of rake. This can vary based on conditions, grass types, and seasons. I would find out where your at and if your less than 1/4" I'd adjust accordingly. If that improves it but you still see some "excessive" plugging you may want to go as high as 3/8". The 52" deck can really do some goofy things once you hit 1/2" sometimes so I wouldn't go that far until you've tried 1/4" and 3/8" settings.

    Also how often are your cutting, how tall is the grass when you start and what is the cutting height set at. You may also want to double check the actual cutting height. I had one a while back that was cutting about a 1/2" low, when we re-leveled the deck and raised it to where it should have been the problem went away.

    With the low hours you have on the machine it's unlikely you've got a problem but it is still possible. Once in a while the idler arm will feel fine but will begin to hang up a little bit as the pivots warm up. It's tough to tell if the problems getting worse because the arms starting to hang up or because the deck is beginning to fill up on its own.

    This may be a good time to get the dealer involved and have the machine looked at.

    The electric clutch does actually stop the blades from spinning. Keep in mind the blades are spinning at close to 200 mph. If you don't put a brake in there they would continue to spin for quite some time. If you disengage your blades at that speed you can increase the wear to the brake componants which can decrease the life of the clutch.

    Let me know what you find out.

    Thanks

    Terry
     
  8. Doc Pete

    Doc Pete LawnSite Gold Member
    Posts: 3,469

    I agree. My Hustlers are fine in dry grass but suffer more than my helpers "old ferris" WB in wet grass.........
     

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