JTL Posted October 29, 2013 Report Share Posted October 29, 2013 First start of day - and only then - crank and run up to temperature - governor on and run up to 80% and let governor take to 100% - then raise collective approximately 1/2 - 1 inch and roll throttle off for low rotor warning system check - engine starts running rough and sputters between 90 - 100% - lower collective governor stabilizes engine at 100% - and can not (will not) do that again until first start next day - not morning sickness - just changed exhaust valve guides, pistons, rings, checked springs, microed everything - no help - tried new mags - especially right mag with tach points, checked timing , gapped points, new plugs, new governor control unit - help help - lost JTL 7 Quote Link to comment Share on other sites More sharing options...
ridgeline Posted October 29, 2013 Report Share Posted October 29, 2013 Had a similar problem once a couple years ago. Cant recall what exactly it was... I thin the guy who solved it is on here... Find Helidude Quote Link to comment Share on other sites More sharing options...
heli_08 Posted October 29, 2013 Report Share Posted October 29, 2013 Have you tried playing with the mixture? Or changing the governor under the copilot seat? Sometimes the friction plates in the gov get a little sticky, might have an adverse affect first time in the morning? I know mixture can be an answer to about 90 percent of engine problems you'll see on a 44 as well, just a tweak here or there can make a difference, also engine control rigging. Good luck and let us know what you find! 1 Quote Link to comment Share on other sites More sharing options...
helidude Posted October 29, 2013 Report Share Posted October 29, 2013 We have had similar symptoms with some of our Raven II's but only in temperatures approaching -30C. It has been very difficult to troubleshoot as it only happens in very cold weather and unless we do the trouble shooting outside, we can't reproduce the symptoms. Not to mention -30 weather is not as common as it used to be. We think something either in the fuel control or the spider valve is causing the fuel mixture to be excessively rich, until the engine warms up and the symptoms disappear. Will keep you posted. Quote Link to comment Share on other sites More sharing options...
rc_jeepin Posted November 6, 2013 Report Share Posted November 6, 2013 the fuel mixture is only effective at idle speeds, the mixture has no effect at 100% its a different circuit within the fuel servo. If you have a tail wag and cant get rid of it by leaning out the mixture at idle, the fuel injector bleeds may be dirty or clogged seriously enriching the mixture in the respective cylinder. cleaning them in an ultrasonic cleaner in hoppes #9 will clean them right up. I have never heard of the issue your having, i would also suspect the fuel servo itself, or the spider, the valve in the top of the spider might be sticking in the cold... then heats up, loosens up and closes. Quote Link to comment Share on other sites More sharing options...
Heliian Posted November 10, 2013 Report Share Posted November 10, 2013 double check the rigging and make sure 100% that the mixture is hitting and staying at the stop and throttle is rigged correctly. Check and clean the fcu inlet filtre and make sure the fuel pumps are working properly. Quote Link to comment Share on other sites More sharing options...
heli_08 Posted August 2, 2014 Report Share Posted August 2, 2014 Hey JTL any news on this? I haven't worked on a 44 for over a year now (thankfully) but my OCD was kicking in with this unanswered question... 1 Quote Link to comment Share on other sites More sharing options...
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