scag deck help

Discussion in 'Lawn Mowing' started by skurkp, Nov 1, 2005.

  1. skurkp

    skurkp LawnSite Member
    Messages: 248

    I have an opportunity to purchase a 60" Z scag. The owner tells me that the deck belt jumps off the pulleys when the mower is accelerated. He thinks the reason is the deck is bent. I have looked at this mower really well and don't think the deck is bent. The mower runs well and at idle the belt stays on just fine. The shafts look tight and straight. Have any of you had this problem, if so what was the cause?
  2. grassmanvt

    grassmanvt LawnSite Senior Member
    Messages: 906

    Strectched or wrong belt? Pulley bad or bent? belt keepers broke or missing, (not sure if scag uses them but I know I had a toro with that issue), loose spindle? Just a few thoughts.
  3. The Captain

    The Captain LawnSite Senior Member
    Messages: 607

    My first thought is the belt tensioning spring is weak or the belt is streched or wrong for the unit. Ask the service dept. at your dealer.

    The Captain
  4. twj721

    twj721 LawnSite Senior Member
    Messages: 619

    might even be a bad spindle like a bearing missing or something to that effect
  5. Envy Lawn Service

    Envy Lawn Service LawnSite Fanatic
    Messages: 11,087

    Well, you always want to hope for the best but...

    I CAN tell you it is hard to see big imperfections in a mower deck, even if you have a good eye for it. I've seen decks that proved to be dimpled, twisted, buckled, ect pretty bad, that were not easily detectable by eye, but could be seen in the cut.

    The good news is, I've never seen one bad enough to make the belt jump off.

    So check the deck out throughly.
    I've got a hunch this might be verticle pulley alignment or other items already mentioned.
    See if the seller will let you 'take it to be looked at' at which time you will do the looking.

    If so, I can help you figure it out one way or the other.
  6. Jpocket

    Jpocket LawnSite Silver Member
    Messages: 2,281

    I doubt that deck is bent, but i would make that the selling point to get the price way down, and if it is you saved enough money to go find a nice used deck or a parts machine. How old is the mower how many hours?
  7. skurkp

    skurkp LawnSite Member
    Messages: 248

    The mower is 5 years old. It is in great shape, I know the owner and he mows long grass and only used the mower on a few jobs for trim work. If the mower needed repairs it went to the shop and was repaired correctly. The only reason he does not take it now is because he purchased a Landpride finish mower that connects to his tractor. The reason I wanted the mower is that I own 3 Hustlers and wanted this as a back up.
  8. skurkp

    skurkp LawnSite Member
    Messages: 248

    O.K. I purchased this scag. Runs great needs tires and the belt keeps jumping off when in high rpm. I checked the pulleys, and the middle pulley was a little high so I brought it down and still the same problem. From what I can see the belt looks to be a little long, it is the belt that is called for by scag, actually I went to Landsdowe Moody and the belt that they wanted to give me was a little longer. When the deck blades are running in low rpm the belt stays on and there really is nothing that seems out of the ordinary. When the rpm's are higher the belt at the longest distance from the gear drive to the first pulley seems to jump around a lot. I was hoping someone may have had this problem before and could help me out.I could not see any way to adjust tension on this deck maybe I am overlooking something? It is a scag stt-61.
  9. mslawn

    mslawn LawnSite Senior Member
    from LA
    Messages: 483

    Back when I had a scag 61' I had this problem-changed belt and fixed the problem. It was not stretched that I could see, but it had a crack on the top side and only thing I could figure it was something to do with the wear on the belt and the crack along the top of the belt.:confused:
  10. chuck bow

    chuck bow LawnSite Senior Member
    Messages: 701

    Had the same problem on my 52 in scag and it was 2 different things that contributed to the problem Number 1 the belt was stretched ( to look at it you wouldnt know it was stretched and number 2 was the bearings in the idler arm were shot ...... all said this was caused by a weak tensioner spring when they replaced all 3 things problem was solved

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