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  • Re: Sleepy boxes (Ducati ignition modules)

    by » 5 weeks ago


    Take a gallon Ziploc type baggie and put so ice in it. Don't over fill and make it too bulky. Kind of flattened. Now wrap the ice bag around the two modules and wit about 25-30 minutes. Then apply full choke and crack the throttle and try a start. If it cranks right up you have your answer. Replace both ignition modules. Just had a guy do this two days ago with symptoms just like yours. It started right up like a new engine.


    Roger Lee
    LSRM-A & Rotax Instructor & Rotax IRC
    Tucson, AZ Ryan Airfield (KRYN)
    520-574-1080 Home (TRY HOME FIRST)
    520-349-7056 Cell

  • Re: Sleepy boxes (Ducati ignition modules)

    by » 5 weeks ago


    This is where my understanding of electrics becomes challenging! What is the effect of cooling the modules with the ice packs? For some reason I had been led to believe they like warmer temperatures rather than cold? 

    Time to get the multimeter out again! 

    One more thing. The chap with the Eurostar has in fact decided to buy two brand new modules (for peace of mind). His engine is a 912UL without soft start capability. He mentioned the modules he was buying had integrated soft start (I believe all the new modules have this?). Am I correct in assuming that the only way he can utilise the soft start capability is to upgrade his flywheel to the newer type (ie. integrated soft start cannot be used with the old style flywheels)? 

    I was also told that the soft start is not required so much for the 80Hp engines as they operate at lower compression. Is this true?

     


  • Re: Sleepy boxes (Ducati ignition modules)

    by » 5 weeks ago


    This is where my understanding of electrics becomes challenging! What is the effect of cooling the modules with the ice packs? For some reason I had been led to believe they like warmer temperatures rather than cold? 

    Time to get the multimeter out again! 

    One more thing. The chap with the Eurostar has in fact decided to buy two brand new modules (for peace of mind). His engine is a 912UL without soft start capability. He mentioned the modules he was buying had integrated soft start (I believe all the new modules have this?). Am I correct in assuming that the only way he can utilise the soft start capability is to upgrade his flywheel to the newer type (ie. integrated soft start cannot be used with the old style flywheels)? 

    I was also told that the soft start is not required so much for the 80Hp engines as they operate at lower compression. Is this true?

     


  • Re: Sleepy boxes (Ducati ignition modules)

    by » 5 weeks ago


    Electronics always PREFER the Cold at least to temps well below what is seen in nature but can also TOLERATE temperatures well above natural temperatures also.

    - - -

    This is what I believe the Flywheel story to be...

    The Ignition Modules originally had no Soft start capability.

    The trigger Cams on the flywheel are raised tabs that carry the magnetic field out to the trigger coils at the proper time.

    As the Trigger Cams pass the Trigger coils, they produce two electrical pulses; a Positive one as the leading edge passes and a Negative One as the trailing edge passes.

    The ignition modules use the leading Edge pulse for normal timing.

    The trailing edge pulse was ignored and just occured at an unspecified time delay After the first one.

     

    Later it was found that if the spark could be delayed during starting, it was much easier on the starter and the engine in general.

    The solution was to use the trailing edge trigger pulse whenever the starter was energized and for 3-5 second afterwards.

    This produced the Soft-Start and reverted to normal timing a few seconds later after the engine had achieved a normal running speed.

     

    The original Trigger Cams produced the desired timing delay but it could be made even better if the Cams were widened so the trailing edge was delayed to 4° BTDC.

    This resulted in the newer Flywheel with trigger cams with purposely dimensioned widths insted of the original arbitrarily dimensioned cams.

    Both flywheels will produce a soft-start and run exactly as intended at power.

    The difference is that the newer flywheel will produce a softer start than the original flywheel.

    The Original Flywheel will produce a noticable soft start, just not as soft as the new flywheel.

    And of course, Rotax specifies replacing the original flywheel with the newer, better flywheel.

    - - -

    Roger, What say you?

     


    Bill Hertzel
    Rotax 912is
    North Ridgeville, OH, USA
    Bill.Hertzel@Yahoo.com
    Clicking the "Thank You" is Always Appreciated.


    Thank you said by: RotaxOwner Admin

  • Re: Sleepy boxes (Ducati ignition modules)

    by » 5 weeks ago


    Well you guys are just amazing!! 😃

    Am I right in saying then that if the newer modules with integrated soft start capability are installed but the signal wire into the 6th connector block hole is NOT connected to the solenoid/ starter the soft start will not be utilised (leading edge trigger pulse only) and neither will the modules be damaged as a result of not being wired in this way?

    There is equally no harm to the modules, or the engine of wiring up the soft start on an engine with the old style flywheel it’s just that the softer start achieved will not be as per Rotax recommended specifications?

     

    Thank you so much for your replies 

     

     


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