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BullyHawk Soft Start Install + ROTAX Questions


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My Sky Arrow has had a problem starting when approaching 30ºF and colder. It would crank one or two blades, then kick back hard and the starter would disengage.


I realize I may have already damaged my starter sprague clutch, but went ahead and installed a Soft Start Module yesterday (my Sky Arrow is Experimental, so I can do that). Just over $200 and available from Lockwood and others.


For those unfamiliar with it, its a device that retards the ignition timing on one ignition circuit as long as the starter is engaged. A little video of it is here:




Installation yesterday took about 4 hours, a large part of it being the pre-install ground and flight temp checks of the module location. My installation was made easier by the fact that I have independent ignition switches, though I had to use a continuity tester to verify which switch controlled which ignition module. (In my case the "IGNITION 2" switch is the one that grounds the upper module, the one that the Soft Start Module hooks up to). I'll post a couple photos of the installation later. In any case, started up smoothly on "IGNITION 2" and a test flight was uneventful.


Let me end here, and post my other questions below...

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1) I also ordered and received the conical oil pressure "ball". Interestingly, the invoice says something like "Install only if necessary". My Sky Arrow has always had rock-steady oil pressures, with the only exception being a marked drop a few minutes after a very cold engine start, which the ROTAX manual addresses. I know the conical "ball" is required for the 2,000 hr. TBO, but being Experimental, I don't think that concerns me directly (and, at about 200 hrs now, would not be a factor for many years).


Question: in my scenario, would you replace the oil pressure "ball" or leave well enough alone?


2) I have coolant leaks from the two pipes on the front of my engine (well, the rear, actually, but my engine is mounted "backwards").




I'm going to have a ROTAX mechanic help me with those repairs next week.


I had someone ask me which coolant cap I was using. I didn't know, but he said on his plane he had gone to a .9 bar cap from the 1.2 bar cap and it had cured his coolant leaking issues. When I had the cowling off yesterday, I have the 1.2 bar cap. Suggestions?


3) If I have damaged my starter sprague clutch, how involved is the repair? Specifically, how many hours are involved and what is the parts cost?


Thanks - I'm sure I'll have more questions to follow!

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Soft Start Module in place, with inline connectors, ground and 1.2 bar coolant cap:




Connection to starter relay (I still have to heat-shrink the tubing):




It hard to capture how pretty the moon was last night when I put the little Sky Arrow to bed:



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