Vic Posted June 16 Report Share Posted June 16 Rotax issues today that broke a Nerve, I have a 912 uls with old non soft start modules that I struggled to start today. I want to say my battery was not fully charged which could have been the reason initially. after I failed to get it going I stuck in on the charger. After a good charge and a little fighting with her I was finally able to start it up but I had to play with the throttle and crack it open further than usual. Once it was running it hiccupped, so I decided to test the mags at 2000rpm. As soon as I went to check the first mag it died. Took forever to fire it back up again, had to put it back on the charger because I was spinning it so much I drained it. Once I got it going again I decided to do another 2000 rpm mag check. It did not die on the first mag but the second mag this time. Once again I had to fight to get it started again. On the next run I decided to let the engine warm up more and do a normal mag check at 4000. This was fine. Then did a mag check again at 2000. This was fine except one mag didn't drop rpm at all, which was odd. I shut down, took a moment to get my camera out to record this and fired back up with no issues. Ran the same tests again an everything ran as expected. Rpm drops on all mags at 4000 and 2000rpm. I taxied around for what seemed like half an hour waiting for something odd to happen and it never acted up again. I decided to not fly, collect my thought and determine if I have failing modules or I rushed a mag check with a not so hot engine and weak battery. From what i know about rotax,the battery would not be an issue for ignition modules once the engine is running, but a weak battery could be the reason i had such a hard time starting even if it looks like the prop is spinning fast enough to fire . I don't know what to think regarding these modules. Why they would run fine at the end of the day after giving me such grief all morning. Maybe I have a bad wire, maybe these modules deteriorate slowly over time and can act sporadic. Quote Link to comment Share on other sites More sharing options...
Roger Lee Posted June 16 Report Share Posted June 16 The battery could be contributing, but it sounds like it more likely is either the ignition switch. Pull out that lower panel and make sure all wire screws are tight. If this doesn't help you may be buying new modules. Quote Link to comment Share on other sites More sharing options...
Vic Posted June 16 Author Report Share Posted June 16 Thanks roger. Is there a diagnostic page in the rotax manual for the ignition switch. Continuity checks? Quote Link to comment Share on other sites More sharing options...
Roger Lee Posted June 16 Report Share Posted June 16 No, because of different Mfg installations. All the switch does is basically ground out the engine so it shuts down. A lose wire can cause your issue. Make sure all are tight on the back of the switch. Quote Link to comment Share on other sites More sharing options...
Vic Posted June 16 Author Report Share Posted June 16 Thanks roger. Well I checked for lose wires, tightened them all down, nothing seemed suspicious there. My battery was 100% charged from over night, and she started right up, I don't think I counted one prop rotation before it kicked over with full choke and throttle at idle. Did a quick mag check cold at 2000rpm and all drops as expected, got it warm and did a 4000k rpm mag check and all drops as expected. Hmmmp, low battery yesterday and maybe some flooding of the engine, mags appear fine this morning and if I didn't have all my issues yesterday I'd say today couldn't have gone better. Quote Link to comment Share on other sites More sharing options...
Anticept Posted June 18 Report Share Posted June 18 Sprag clutches are expensive, if you can't get it to start easily or the prop isn't turning fast, you should stop immediately and put things back on the charger or swap the battery. It's close to a 2k job to replace the sprag. It is, relatively speaking, a weak point on these engines. Quote Link to comment Share on other sites More sharing options...
Vic Posted June 19 Author Report Share Posted June 19 Here a video of my shutdown today. Does that prop stopping look like a bad spray? VID_20240619_131331965.mp4 Quote Link to comment Share on other sites More sharing options...
Vic Posted June 19 Author Report Share Posted June 19 Here another video VID_20240619_131541928.mp4 Quote Link to comment Share on other sites More sharing options...
Anticept Posted June 19 Report Share Posted June 19 Sprag is only for starting. You mentioned fighting with it trying to get it to start. Don't do that. Quote Link to comment Share on other sites More sharing options...
Vic Posted June 19 Author Report Share Posted June 19 Thanks, yea battery stays on the tender all the time now. Started up pretty easy today. Those videos are on shutdown so glad to hear it's not an issue Quote Link to comment Share on other sites More sharing options...
Vic Posted July 6 Author Report Share Posted July 6 I think I need new modules. I had a no luck getting my engine started today with a full battery that's been on the charger all week. I have a silver starter motor, not the old black style that people recommend upgrading away from. MY engine is from 2004, which means I probably have the 4 plug wires and not the new style 6 plugs that are being build/installed today? Is there a document somewhere depicting what or how to use the new plugs with older module wiring harness? Quote Link to comment Share on other sites More sharing options...
Tom Baker Posted July 6 Report Share Posted July 6 The old style modules have one plastic plug, and then individual wires for the rest per module. The new style has two plastic plugs per module. The change to the new style came in 2004. The older style modules are still available, part number 965-446. If you have the new style the part number is 965-445. With the new style you will have to add a wire to use the soft start function of the module. From SI-912-013 the new ignition started with serial number 5,643.680 for the ULS. Quote Link to comment Share on other sites More sharing options...
Vic Posted July 6 Author Report Share Posted July 6 Thank you very much Tom! 5644302 is my sn so I'm must have the new style and I will want to enable the soft start feature Quote Link to comment Share on other sites More sharing options...
Roger Lee Posted July 6 Report Share Posted July 6 Just additional info; When you go from the older ignition modules to the new soft start ones you’ll only get partial benefit. For full soft start feature you’d have to also replace the fly wheel that has different timing marks. Quote Link to comment Share on other sites More sharing options...
procharger Posted July 9 Report Share Posted July 9 I replaced flywheel on mine with soft start modules years ago. Quote Link to comment Share on other sites More sharing options...
Vic Posted July 9 Author Report Share Posted July 9 I have new modules on the way. Mine are not reliable, and they are original from 2004. So they are old and in the group know to have issues, Tom at FD said it was amazing they lasted this long. I also have the Y harness coming so I will plug that into the open slots in both modules and connect the end to the signal wire on the solenoid. Are there any other items I'm missing? I am not putting on the new flywheel, if it's not going to harm anything I'd rather just enable soft start and leave everything else alone Quote Link to comment Share on other sites More sharing options...
Tom Baker Posted July 9 Report Share Posted July 9 Sounds like you have it covered. Quote Link to comment Share on other sites More sharing options...
Vic Posted July 10 Author Report Share Posted July 10 Thanks Tom, these modules look tough to get with the airbox butting up against them. Do you guys take the air box off to get better grip on the module connectors? Quote Link to comment Share on other sites More sharing options...
Ulmo133 Posted July 10 Report Share Posted July 10 14 hours ago, Vic said: I have new modules on the way. Mine are not reliable, and they are original from 2004. So they are old and in the group know to have issues, Tom at FD said it was amazing they lasted this long. I also have the Y harness coming so I will plug that into the open slots in both modules and connect the end to the signal wire on the solenoid. Are there any other items I'm missing? I am not putting on the new flywheel, if it's not going to harm anything I'd rather just enable soft start and leave everything else alone Same for me, almost 1000 hours and the module from 2004 I move them and don't have to remove the airbox to disconnect them from the wire. Quote Link to comment Share on other sites More sharing options...
Roger Lee Posted July 10 Report Share Posted July 10 You shouldn’t need to remove the air box. Quote Link to comment Share on other sites More sharing options...
Tom Baker Posted July 10 Report Share Posted July 10 It is tight, but removing the airbox is a bigger hassle than working around it. Quote Link to comment Share on other sites More sharing options...
Vic Posted July 10 Author Report Share Posted July 10 Sure, Thanks Tom, hopefully I can get these new mods installed tomorrow evening and but this to rest. Never good feeling when you head out to the airport and its a crap shoot on whether or not your engine decides to fire up. I'm just glad I did not get stranded away from home base. Quote Link to comment Share on other sites More sharing options...
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