912iS Starting

Thanks I get a throttle position readout on the EMSIS I have installed

Peter,

1. When the engine does finally start, does the throttle position you are using require you to reduce or add throttle to reach 2100 RPM?

2.  You mentioned having a "soft start" on the engine, do you mean an automatic circuit to control the start power?  I'm not familiar with a soft start module for the 912is.

The reason I mentioned to try and crack the throttle is I have found some 912iS engines with excessively low idle rpm and idle rpm wasn't mentioned in the original post.

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ALL:  This is a fuel injected engine.  There is no traditional "soft start"system as known in the carb 912.  The ignition timing is all controlled by the computer and not a mechanical device like the flywheel and the start delay is part of the circuit, there is no traditional circuit board as on the other engines.  

All injected Rotax must have the throttle open somewhat for start, otherwise the mixture at start is too lean.  The operators manual has a very specific start requirement for throttle position to allow for enough fuel to fire up, not enough and it will be very difficult.  The correct way is to have an instrument system that will show the throttle position in %, it is part of the CAN-BUS output and a number of monitors from suppliers display this.  It is also very useful to know when flying so you can tell when you are running in ECO MODE range of throttle opening.  It is important when you do start the iS engines to bring the RPM up to at least 2500 for a few seconds.  This is required to excite the generator so both the primary side that runs the engine and the side that gives you all the power are both working.  

You can check out the start sequence in the operators manual.

Cheers

Rotax Wizard,

I'm aware that there is no soft start for the iS engine, but the OP had mentioned he had one installed on his 912is.  I asked the question to find out what device he was actually referring to, and if that device (whatever it is) could be contributing to the starting problem. 

While I agree with the importance of throttle position during startup, that fact that his engine always starts right up on the second attempt makes me think his procedure is correct, including throttle position.  His first attempt always fails. Then he waits a couple minutes for the starter to cool and tries the SAME procedure again and the engine immediately starts.  So the question is: what changes in that two minutes?