I have a Rotax 503 SCDI engine with the oil pump lever marks set ( a long time ago by the previous owner, not reachable now) to line up not for the IDLE ~2000 RPM, but for 3000 RPM. When I notice it I thought maybe it was because of only a single carb  So, I hoped to find some kind of possible cause/explanation for that. Also, what does "E-3" on an oil pump lever mean?

                         Thank you for your help/advice.GR

9029_1_Mikuni oil pump - 1.jpeg (You do not have access to download this file.)
  • Re: Rotax 503 SCDI oil pump setting

    by » one year ago

    hi Georgi


    The lines should match at idle speed (2000)  You will note that usually there is also a small punch mark on the level as you open the throttle and when the lever reaches that point and beyond it is at its max flow rate.  The flow reduction only occurs from idle to that mark.  Generally it is about 65/1 ratio at idle where there is very little load on the engine.  As we reach into  the midrange running it will have moved to max flow about 50/1 ratio.  

    The oil pump on the type 503 is rigged differently from the type 582 and as such requires a different lever.  The E3 is simply a Mikuni marker for the reverse direction pull and different spring used on the type 503.  



    Thank you said by: RotaxOwner Admin, Georgi Rumiansev

  • Re: Rotax 503 SCDI oil pump setting

    by » one year ago

    Thank you again, Rotax Wizard. The engine was run like that (3000 RPM) for about 140 hrs. So, I don't expect much harm (hope). Now I need to find a good video/tutorial about how to decarb piston heads.

  • Re: Rotax 503 SCDI oil pump setting

    by » 10 months ago

     Sorry to drag the topic, but Yesterday I watch Rotax 503 Installation DVD from CPS(California Power Systems) and they recommended to set lever mark line for 3000 RPM, not for 2000 RPM idle. It is maybe older DVD (but I bought it Yesterday April 23d 2022). So, what could change?

    32489_2_Oil pumplever set.jpeg (You do not have access to download this file.)

You do not have permissions to reply to this topic.