CH750 DSAM question

Discussion in 'Mechanic and Repair' started by East Coast Lawn Choppers, Nov 12, 2009.

  1. East Coast Lawn Choppers

    East Coast Lawn Choppers LawnSite Member
    Messages: 134

    Restro I'm sure you can help with this...
    My question I guess is how will a mower run with analog sam and digital coils ?

    We had a mower come in with a CH750 0010 it runs like crap when it starts it rares on the starter. Then when it starts it searches for the rpms...
    When checking it out I found a few items... first of all it has the 24 584 36 coils which are correct.... it has a 24 584 09-s module which is an analog module used on the CH25's how bad would that mess with the timing and running, because it also has a 104 24mm carb that there is a tbs out on it that it should be replaced with a 22mm that is the other problem it has.
    This thing should have a 24 025 15-s (58-s) flywheel the 24 584 09-s SAM is to be used with a 24 025 14-s flywheel and the magnets are in a ttally different position. Between digital to analog and then the timing of the coils it runs like crap...
    Should I put on a 24 584 38-2s DSAM or can I get away with a 24 584 31-s which is the one for a 27hp
  2. Restrorob

    Restrorob LawnSite Fanatic
    Messages: 11,029

    If you have the proper coils and flywheel on this 27, I Would surely install the proper SAM for the 27. As you see mix and matching components can cause problems.

    Hope I read you post correctly, I've been taking meds for my bad back the last couple days (foggy)......
  3. East Coast Lawn Choppers

    East Coast Lawn Choppers LawnSite Member
    Messages: 134

    I put the 31-s on it with the 36 coils which are also used on the 27 hp so it is a 30hp with a 27hp DSAM on it. It runs great now except for the stupid 104 24mm carb. I'm going to try messing with the jets and open them up just a little and possible do a throttle stop. (I think one of the things that happens with that carb is when the govenor goes to make up it opens all the way and it is too much for it) I want to see if I can make this carb work he doesn't want to spend the money for the 22mm carb. It is a "recall" item and it states that if it runs bad replace it so it was not something that they called all of them back I guess... But this one does exactly what the buliten said they do with that carb. It has to have the choke on to engage the blades and when it hits hi grass and applies more throttle it will pop and shut off. Too big of a carb and no accelerator pump I hate the two barrell carbs so bad...
  4. tomo

    tomo LawnSite Senior Member
    Messages: 660

    hi ,
    although i cannot state part numbers
    I personally have fitted digital coils to my analouge SAM unit no problem
    [super cedes to this number from memory ]
    U must use digital coils only with digital SAM [obviously]
    As far as i am aware there are only 2x different flywheels
    SAM type
    This advice came from Kohler cust service although 3 yrs ago

    Digital SAM was invented for improved accuracy/control of the advance curve

  5. East Coast Lawn Choppers

    East Coast Lawn Choppers LawnSite Member
    Messages: 134

    Thanks, I guess the 31 & 38 are close
    but I'm pretty sure the 09-s which is used on the 25 has a different flywheel the has the magnet in a slightly different spot in reference to the keyway. Not sure if that is made up with coils or sam because they use the same crank.
    This is a quote right out of the tech documents
    When a module or flywheel is replaced, the proper combination must be maintained, or overall operation and performance will be afected (loss of power, back firing etc )
    There is a chart to go by in the document.
    That is what happened on the one we had here, the problem did correct when we put matched stuff on.

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