tecumseh quits running

Discussion in 'Mechanic and Repair' started by bkvail, Jul 11, 2005.

  1. bkvail

    bkvail LawnSite Member
    Posts: 4

    Older Tecumseh 13 HP riding mower (Ace Special Edition). It would not start, so first thing we checked was the spark plug. It was fouled, so after replacing it, the mower starts, but only runs for 30 seconds to 3-4 min max (it just DIES w/o warning like you turned off the ignition) and will not restart until it has been sitting for several hours or the next day. It will turn over fine, but will just not start. There is no power getting to the spark plug when it is not starting, but there must be spark getting to it when it will start (obviously). Someone suggested that it might be the magneto, but we pulled the flywheel and none of the copper wires on the magneto appear to be broken, and every other wire on the machine seems to be fine. All the safety switches seem to be working. We replaced the ignition thinking that maybe it was shorting out inside, but that didn't fix it - still does the same thing. The closest lawnmower repair mechanic I have been told by several people NOT to take it to him, so I am at a loss what to do. Hoping someone else has had something similar happen to them............
     
  2. Redneckn

    Redneckn LawnSite Senior Member
    Posts: 294

    If it is not sparking when it is not starting. take the little "kill" wire off the armature (spark coil, laminate, ect...) and see if it will spark then. if not, the armature is the problem. if it does spark then, we have an issue elsewhere. like in the kill circuit.
     
  3. Restrorob

    Restrorob LawnSite Fanatic
    Posts: 11,022

    Sounds like a bad coil to me !
     
  4. CCWKen

    CCWKen LawnSite Member
    Posts: 113

    As Restorob says, it could be the coil breaking down with heat. It could also be the ignition module. If it's the old HH130, the ignition module and coil are one unit and VERY expensive. It may be cheaper to convert to an electronic ingnition with a separate auto coil. The problem with this conversion is that it may be hard to start or kick-back very easily. (The stock ignition module retards timing until the engine is running.)

    Put a volt meter (set on ac) on the module feed and watch it during the run test. If the voltage stays up and the engine dies, the ignition module/coil is bad. If the voltage quits and the engine dies, it's the ignition stator winding. (Separate from the alternator winding but on the same stator frame.)
     
  5. Restrorob

    Restrorob LawnSite Fanatic
    Posts: 11,022

    Your right CCWKen, I based my reply on the unit being a Ace S/E which was made by MTD in the 80s . If there was a Ace unit back then with the HH130 engine I had no idea because that was before I got into the business.
    It would also be nice to have model and spec. numbers posted so we could look up the equipment and give a more accurate remedy for the posted problem without having to assume what it is.
     
  6. bkvail

    bkvail LawnSite Member
    Posts: 4

    well, I'm beginning to think it's the coil too. It won't start at all as of this afternoon. It's model #618-0166A and serial #A-097025. I imagine it is from the 80's by the looks of it (we have had it for 2 years) Was told that a coil would be around $50 or so. I imagine there is gapping like points (distance from magnet on the flywheel) that I will have to reset when I put a new one on?
     
  7. Restrorob

    Restrorob LawnSite Fanatic
    Posts: 11,022

    Install the new coil and with the screws still loose pull the coil away from the flywheel and snug the screws,Rotate the magnet in front of the coil and insert any business card between the two (Its the proper gap) loosen the coil screws and let the magnet pull the coil to it, Then retighten the screws.
    Grab the end of the card and pull while rotating the flywheel.
    Check for spark before you plug up the kill wire and afterwards to make sure there isn't a problem with the interlock system, Then install blower housing and go mow.
     
  8. bkvail

    bkvail LawnSite Member
    Posts: 4

    Thanks a million! You guys are great!

    On another note - we had taken the flywheel and magneto (alternator?) off for inspection (someone told us that if there was a broken/cracked wire in the windings, this would cause these symptoms, then we realized that it's just there to charge the battery and a dead battery wasn't our problem, but of course we had already taken it off before this hit us, LOL). The magneto looks like it just bolts back on in one position? I hope.......
     
  9. Redneckn

    Redneckn LawnSite Senior Member
    Posts: 294

    Glad you were able to get it back going. Electrical issues seem to throw a lot of people for a loop for some reason.
     
  10. bkvail

    bkvail LawnSite Member
    Posts: 4

    well, it's not fixed yet! I ordered the coil from Ace and it came in today and it's the WRONG part. So, try try again.....
     

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