24 hp honda

Discussion in 'Mechanic and Repair' started by ctd3500, Mar 27, 2008.

  1. ctd3500

    ctd3500 LawnSite Member
    Posts: 12

    I have a 2004 hustler super mini-z with a 24 hp Honda engine. The engine is having ignition problems. With about 70 hours i lost spark. It became intermitent, sometimes running and sometimes not. I need to get this running for the spring and summer. I also have the bac-vac for it. A lot of money, should run. No one has wants to help, just wants money. It was out of warranty by about a month or 2 when this started. I checked it today and was able to get spark to the rear coil, nothing from the front coil and yes i switched the plugs back and forth. So, I am thinking the coil. But, what about the diode? Coil is $60 for the front and about $30 for the rear. Diode, about $40. It is not the oil switch and does not appear to be the wiring cluster (nice name for all the wires and relays). I would appreciate any help.
    :hammerhead:
     
  2. Restrorob

    Restrorob LawnSite Fanatic
    Posts: 11,022

    Test the diode with a multimeter set on ohms scale, One direction will be open then reverse the test leads and it should read closed.
     
  3. ctd3500

    ctd3500 LawnSite Member
    Posts: 12

    I checked the diode, no resistance or continuity. I still have spark on the rear coil. Is there a difference between the coils? I switched coils then neither worked, put them back and the rear has spark again. I can't understand why the coil in the rear would only fire when on the back (left cylinder) engine unless they are side dependent. Any other suggestions? I just do not want to buy parts I do not need. Thanks for the help.
     
  4. Restrorob

    Restrorob LawnSite Fanatic
    Posts: 11,022

    I just helped someone on another site with a problem such as this, Here is a post I made to him;


    [​IMG]



    If this doesn't look like your system post both the model and type/spec numbers along with the serial number so I can look yours up.
     
  5. ctd3500

    ctd3500 LawnSite Member
    Posts: 12

    I completely disconnected the diode. I believe there should be spark. Only the rear (left) cylinder has spark. When swapping coils I get no spark, put them back to there original location and get spark on the rear (left) again. Cannot get spark on the front. (right cylinder) Honda GXV670 GJAH-1009097 TAE2
     
  6. Restrorob

    Restrorob LawnSite Fanatic
    Posts: 11,022

    OK, The coils do have different part numbers. What the difference is I'm not sure.

    I'm also not sure (it's been a few years since working on one of these Honda's) if the diode assembly must be plugged on the coils in order to check for spark properly, I'm sure they must be on a Briggs Vanguard to check for spark.


    What you need to do is properly test the diode assembly as below, This will either show it being the problem or eliminate it of being the problem.

    The fact that you got no spark on either coil when swapped could be a sign you may have two problems. The diode could have failed and took the coil out with it. Hence, Good coil on failed diode and bad coil on good diode. See, There are two diodes inside that assembly one for each coil so one can spark without the other.


    [​IMG]
     
  7. ctd3500

    ctd3500 LawnSite Member
    Posts: 12

    I tested the diode per your instructions. It checked out OK, reading 240 something with a multi-meter set at 2000k and nothing with the leads reversed. I'm thinking the coil, but wonder if there could be another problem in the wiring harness. With the coils having different part numbers the coils must not be reversible. When I change them back and forth I can only get spark with the rear coil when it is on the rear (left) cylinder.
     
  8. Restrorob

    Restrorob LawnSite Fanatic
    Posts: 11,022

    As I said I'm not sure of the difference between the two coils (spark timing ?).

    But, I can tell you that if there was a problem with any other part of the harness you would not be getting spark on only one coil, You would have no spark at all. Since the diode assembly test shows good replace the non-firing coil then get back to mowing.....
     
  9. ctd3500

    ctd3500 LawnSite Member
    Posts: 12

    Thanks, i'll get one ordered and let you know what happens.
     
  10. ctd3500

    ctd3500 LawnSite Member
    Posts: 12

    Update: I received the new coils. I also put in new plugs. It is up and running again! It seems to be running good, but wish I had a little more power (the bac-vac runs a blower assembly and sucks a fair amount of power. Thanks restrorob for the help.
     

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