The dealer said......

Discussion in 'Lawn Mowing' started by crazycritterguy, Jun 17, 2006.

  1. crazycritterguy

    crazycritterguy LawnSite Member
    Posts: 31

    That when I engage the blades I should have the engine at the max RPM's....scag TT, 27 Koh.....and so, after 125 hours on the machine, I was skimming through parts of the owners manual while "resting" ....in the rest room....and I find that IT SAYS to have the engine at about 75% of max RPM's when engaging the blades...or premature clutch wear.....etc...etc... SO....here is my problem...this dealer has been right on the money about everything else,,,and has sold scag for a long time....does the mechanical work right along side with his shop workers....won't even sell a machine unless he personally puts it together and checks everything....and I remember directly asking him at the time of the purchase if I heard him correctly say to have the engine at max RPM's..twice!...(having just traded a kubota that you had to slow it way down or it would kill the belts)...should I call him and point out this..."potential problem"....should I ask him for a free check of the blade clutch.....what would you do....? What should I do?
     
  2. topsites

    topsites LawnSite Fanatic
    Posts: 21,653

    I would take the manual to the dealer and ask him what he thinks about this bit with the 75% rpm, it seems like this guy is straight up and won't feed you no bs.

    You may still have to make up your own mind, my last dealer was really good but on some things we disagreed, still I respected his opinion highly and took a lot of things he said into serious consideration. I dare say I would likely do the same with your dealer, thou of course you would know better here what to do, how to proceed...
     
  3. deereman

    deereman LawnSite Senior Member
    from USA
    Posts: 518

    Are you getting confused with the break-in procedure with the PTO-Clutch? New mowers you should have throttle at full speed and engage PTO and allow mower to run for 10 seconds..........Disengage PTO and wait 10 seconds........Repeat steps for 12-15 cycles
     
  4. newz7151

    newz7151 LawnSite Silver Member
    from Tejas
    Posts: 2,419

    Not sure how the scags are, but if you look on an eXmark, there by the PTO switch it tells you to engage and disengage the PTO at half throttle.
     
  5. rodfather

    rodfather LawnSite Fanatic
    Posts: 9,501

    we do the same on our Ferris's (wb's and z's).
     
  6. deereman

    deereman LawnSite Senior Member
    from USA
    Posts: 518

    The post that I previously posted is for a 757 Z-TRAK which is what was stated for break-in-procedure. Just thought that I would clarify that
     
  7. Triple R

    Triple R LawnSite Member
    Posts: 244

    Just wondering why the throtle has to be set so high to engage the blades? The way I am thinking is that the higher the rpm's the more stress on the clutch just like a vehicle or am I wrong.
     
  8. 6'7 330

    6'7 330 LawnSite Bronze Member
    Posts: 1,822

    After the break in procedure , previously described by another other poster ,never engage the clutch at max RPM.When the engine is cold, let it warm up a bit engage at half throttle,disengage at half throttle as well.
     
  9. viper00085

    viper00085 LawnSite Member
    from NC/VA
    Posts: 237

    i feel that engaging at 1/2 throttle to full throttle is fine. go with 1/2 throttle if it does not bog your engine down badly. If your eng bogs and struggles you could have problems with throwing your belts from the sudden snap of the belt trying to engage. I spoke to a Toro engineer about this 2 years ago when this whole thing of engaging decks at full rpms came about, he explained its all about "belt wrap" around the puleys and how much slip the manufacturer wants vs that sudden snap and possibly belt thrown off and spring failure if there is not enough power to slip the belt for that brief seconds of initial engagment.
     
  10. lawnmaniac883

    lawnmaniac883 LawnSite Silver Member
    Posts: 2,613

    You can look at this two ways. Engine RPM's are low therefor your alternator/charging coil is not putting out much amperage. Clutches draw madd amperage when engaging and by not having the engine at max rpm's you can actually slip the clutch just as much because there is not enough power to quickly engage.

    The other angle of this is full throttle engagement will have much more amperage but high rpms tend to put some wear on clutches. I used to engage at 1/2 throttle or less on my 44z but after having recent engine issues with bogging and a poor running condition, I can now only engage at wot or engine bogs and dies. What I have found is the time it takes for the clutch to stop slipping and engages is almost the same at all rpm's.

    As for disengaging at 1/2 throttle, screw that. Productivity comes before equipment in my book and by stopping, slowing the engine rpms down, disengaging clutch, speeding engine up, going back to trailer just seems like forever. I just kill the blades from WOT and leave it be. When the clutch wears out a new one is only 150-200 bones.
     

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