Blades won't engage Correctly-Scag Walk Behind

Discussion in 'Mechanic and Repair' started by clean_cut, Apr 7, 2010.

  1. clean_cut

    clean_cut LawnSite Bronze Member
    Messages: 1,327

    I have a 52" Advantage deck Scag walk behind, whenever I try to engage the blades the mower sounds like it tries to get them going but a belt doesn't catch or doesn't have enough power or something. It makes the initial sound of starting the blades, but then sounds like they just get shut off. Sometimes I have to pull the pto switch three or four times to get the blades to engage completely.

    This began happening recently while I was preforming a spring cleanup for a lady with a LOT of trash, sticks, rock, etc. in her yard, I'm sure I hit some but not anything to seriously damage the mower. I also have a bit of orange twine (from a straw bale) wrapped around the blade and spindles, but I don't think that would hurt anything.

    It couldn't be any safety switches or bad connections because the blade wouldn't begin to engage if there was a bad connection, right?

    Also, the belts are tight, maybe too tight, I don't have any tool to measure them, is there a way to tell by hand?

    Has anyone had this problem or know how to fix it? Any help would be greatly appreciated!

    Thanks and God Bless you all!
  2. DT Lawn Care

    DT Lawn Care LawnSite Senior Member
    Messages: 850

    Remove tension from the belts and check all of your spindles and pulleys for resistance, grease as needed. If everything spins fine, check your air gap on your PTO and adjust to spec. Good Luck

    Also, are you too lazy to get underneath and remove the twine and crap hahaha
  3. piston slapper

    piston slapper LawnSite Platinum Member
    Messages: 4,337

    remove the hood covering the deck. Check the wires going to the clutch. The way the wires are routed, they get damaged pretty easy.
  4. dutch1

    dutch1 LawnSite Silver Member
    from Jayhawk
    Messages: 2,249

    The best I can do as far as numbers on the coil is KL 1. There are three wires exiting the coil--1 small yellow wire grounding to the core of the coil, a long black wire going to the kill switch and the plug wire.

    I had checked out the kill wire thoroughly for any bare spots that could have led to premature grounding.


  5. clean_cut

    clean_cut LawnSite Bronze Member
    Messages: 1,327

    Thanks so much guys, I'll try to get to it later today.

    No, I haven't been too lazy to remove the twine, well I probably could have, but I was quite busy. Finishing a 2 day cleanup, trimming hedges, mowing a lawn and picking up a new customer and cleaning his yard, Im liking the work though :)

    Thanks again guys, God Bless!
  6. clean_cut

    clean_cut LawnSite Bronze Member
    Messages: 1,327

    Thanks again guys, I took off the twine, but the blades still didn't operate correctly, so I turned the bolts on the air gap clutch 1/4 to 1/3 turn each and it all worked well!

    I still need to find the exact measurements of the gap/spacing, I checked my owners manual, but couldn't find anything about it, I'll keep looking though, anyone know where this info can be found? Maybe the section w/ the bolt torque and belt tension.

    Thanks again guys, God Bless!
  7. DT Lawn Care

    DT Lawn Care LawnSite Senior Member
    Messages: 850

    Normally it is .012 to .015, measure with feeler gauges. Good Luck
  8. clean_cut

    clean_cut LawnSite Bronze Member
    Messages: 1,327

    Thanks, I just was out mowing and found that the blades DON'T engage right now. They seem almost worse. I'll try to adjust them again and I'll try adjust it right.

    Does anyone know if the clutch needs to be removed from the mower to preform the proper adjustment? The clutch just seems very difficult to adjust, much less, adjust correctly with a feeler gague.
  9. DT Lawn Care

    DT Lawn Care LawnSite Senior Member
    Messages: 850

    Haha, no. Trust me, it's easier to do this than remove the engine from the mower and then remove the clutch from the engine. When adjusting, tighten each bolt a TINY bit at a time, keeping the gap pretty much the same all the way around all the time.
  10. clean_cut

    clean_cut LawnSite Bronze Member
    Messages: 1,327

    Are you sure I have to remove the engine?

    Check out this link

    Check page 10 (shown as page 8 on the actual manual)-Engine Deck

    The clutch seems to be item 21, and held on only by 1 bolt (item 32)

    It doesn't appear that I need to remove the engine, but maybe I don't understand something, am I right?
    Last edited: Apr 14, 2010

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