---------------------------------------------------------- RotaxEngines-List Digest Archive --- Total Messages Posted Mon 09/28/09: 7 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 11:48 AM - Re: 912 Q & A (Les Goldner) 2. 11:48 AM - Re: Rotax 912 Charging Problem (Hugh MCKAY III) 3. 11:57 AM - Re: Re: Rotax 912 Charging Problem (Pete Christensen) 4. 12:07 PM - Re: Rotax 912 Charging Problem (rampil) 5. 01:13 PM - Re: Rotax 912 Charging Problem (paul wilson) 6. 03:04 PM - Re: Re: Rotax 912 Charging Problem (Hugh MCKAY III) 7. 06:44 PM - Re: Re: Rotax 912 Charging Problem (Hugh MCKAY III) ________________________________ Message 1 _____________________________________ Time: 11:48:51 AM PST US From: "Les Goldner" Subject: RE: RotaxEngines-List: 912 Q & A Dashwood, I like people to use their names when asking for help. I don't particularly like answering "dashwood" As to your problem. If you really want help you need to be a bit more specific. For example, what are your temps at cruse, and at the two rpm levels you mentioned. Also you confuse me talking about temp sensors on Cylinders 3 and 4. Why are you mentioning this? Do you have CHT problems as well? I'll try to help... On my 912 two turns in the carb clamps would not cause a problem unless they were practically falling off. Your choke needs to be sync'd. The problem may be with the cables sticking. Once you check this you will need to follow the Rotax manual's procedures for getting the chokes lined-up. However, the choke (really an "enricher") only operates when you start the engine at idle so you can test the impact of your choke on your problem if you start the engine at a higher RPM setting so the choke won't kick-in. Les -----Original Message----- From: owner-rotaxengines-list-server@matronics.com [mailto:owner-rotaxengines-list-server@matronics.com] On Behalf Of dashwood Sent: Monday, September 21, 2009 3:56 PM Subject: RotaxEngines-List: 912 Q & A I purchased this 912 ul over a year ago. Things have been running smoothly ( oil changes and carb balanceing as required). latley i'm getting overheat warning lights on exhaust pipe "2" when i start to throttle back for landings 4700 to 3500rpm. at normal cruse and full throttle everything is green. I only have 2 temp sensors one on cylinder 3 and on 4which one would normally be temp sensor 2.. prolly the builders decision. next question would one carb clamp being loose and needing 2 full turns to tighten cause lean burn at some throttle settings. question 3 would the primer/ choke valves not being totally closed cause this.( cable stop was loose ,moving,binding.) now fixed. question 4 does the throttle arm want to stay in one position. while the engine is running normally or will it tend to close to idle or advance gradually to full throttle. ignoring the full throttle safety spring. the spring on one side pulls strongly to the full open stop but the other side is we! ak and will leave the right side about 1 mm short of the full throttle stop. a very light flick of the throttle cable and it pops to full. (engine off) cant see any binding a problems with this cable and assuming that engine running would vibrate enough to move to full as it should. Will be changing both spring asap anyway. I have 100 hrs on the plugs and am changing them tomorrow. was just wondrin if I'm on the right trac or if anyone had other thoughts. Read this topic online here: http://forums.matronics.com/viewtopic.php?p=264224#264224 ________________________________ Message 2 _____________________________________ Time: 11:48:51 AM PST US From: Hugh MCKAY III Subject: RotaxEngines-List: Re: Rotax 912 Charging Problem I have a Rotax 912 UL engine on an Allegro 2000 LSA. Recently I have had to replace my battery (12V 18Ah) because of it's inability to crank the engin e. Prior to replacing the battery I noticed my combination Volt/Amp meter s howed only 12 volts while flying. Usually the voltmeter shows about 13.5 vo lts at start-up while the engine is running on the ground and while flying. After replacing the battery, and starting the engine the voltmeter returne d to 13.5 volts. However, when I began to close certain circuit breakers en gaging the front landing light, the two wing tip landing lights, the two wi ng tip strobes, and the nav. lights I noticed the volt meter dropping back each time I engaged one of the breakers until finally the volt meter again was indicating only about 12 volts just as before. I have a "no charge" red light in the battery charging circuit that comes on if the battery is not being charged while the engine is running. This light normally does not come on unless the engine is at very low rpm ( aprx.1400 rpm). This is not normal for my engine for my idle speed is set at 1800 rpm. - I do not know why the voltage is dropping each time I close the breaker for lights described above, or what may be causing the voltage drop. I know I have a good battery, but I don't know if my regulator is going bad, or if t here may be aground some where, or somthing else. Can anyone shed any light on what may be causing this? The engine has only 255 hours on it and I hav e not had any other problems with the engine. Any help would be greatly app reciated. - Hugh G. McKay III Allegro 2000 Rotax 912 UL N661WW - hgmckay@bellsouth.net - ________________________________ Message 3 _____________________________________ Time: 11:57:06 AM PST US From: "Pete Christensen" Subject: Re: RotaxEngines-List: Re: Rotax 912 Charging Problem Had the same problem with my Kitfox III/912. Asked the same questions. Replaced the rectifier/regulator. Problem solved. Pete ----- Original Message ----- From: Hugh MCKAY III To: rotaxengines-list@matronics.com Sent: Monday, September 28, 2009 1:07 PM Subject: RotaxEngines-List: Re: Rotax 912 Charging Problem I have a Rotax 912 UL engine on an Allegro 2000 LSA. Recently I have had to replace my battery (12V 18Ah) because of it's inability to crank the engine. Prior to replacing the battery I noticed my combination Volt/Amp meter showed only 12 volts while flying. Usually the voltmeter shows about 13.5 volts at start-up while the engine is running on the ground and while flying. After replacing the battery, and starting the engine the voltmeter returned to 13.5 volts. However, when I began to close certain circuit breakers engaging the front landing light, the two wing tip landing lights, the two wing tip strobes, and the nav. lights I noticed the volt meter dropping back each time I engaged one of the breakers until finally the volt meter again was indicating only about 12 volts just as before. I have a "no charge" red light in the battery charging circuit that comes on if the battery is not being charged while the engine is running. This light normally does not come on unless the engine is at very low rpm ( aprx.1400 rpm). This is not normal for my engine for my idle speed is set at 1800 rpm. I do not know why the voltage is dropping each time I close the breaker for lights described above, or what may be causing the voltage drop. I know I have a good battery, but I don't know if my regulator is going bad, or if there may be aground some where, or somthing else. Can anyone shed any light on what may be causing this? The engine has only 255 hours on it and I have not had any other problems with the engine. Any help would be greatly appreciated. Hugh G. McKay III Allegro 2000 Rotax 912 UL N661WW hgmckay@bellsouth.net ________________________________ Message 4 _____________________________________ Time: 12:07:51 PM PST US Subject: RotaxEngines-List: Re: Rotax 912 Charging Problem From: "rampil" Hi Hugh, Remember that nasty lump on the rear end of your 912. That's the alternator. It supplies electricity to run things on your airplane when the engine is going. The alternator supplied as an integral part of the 912 can only supply 16 amps or so at 5500 rpm at 13.5volts. When you turn on on enough electrical load, you are asking for more than the poor little thing can supply. The regulator does not create power out of thin air, it only smooths out the voltage until it can't any more. If you don't shut off some of that electrical junk, the voltage will not be high enough to charge your battery. You can put on a new 40A alternator for about $800. It will suck those extra amps right out of your propeller if you do. I would also recommend you read a bit about aircraft or automotive electrical systems. -------- Ira N224XS Read this topic online here: http://forums.matronics.com/viewtopic.php?p=265373#265373 ________________________________ Message 5 _____________________________________ Time: 01:13:39 PM PST US From: paul wilson Subject: RotaxEngines-List: Re: Rotax 912 Charging Problem Your solution is best found by signing up the the aeroelectric list on Matronics. Quickly your volts are to low 13.8 to 14.2 or so indicates a healthy charging system at engine speed just above idle. You have your low voltage light wired wrong. You should have a low voltage indicator light on your battery buss and then it would come on at at voltage below 13. Your battery is not being charged because the output of the reg is way to low. Probably time for a new regulator, but the electric guys will tell you how to determine if the alternator is providing the good stuff to the reg. BTW FYI, a good battery should have more than 12.6 volts after sitting unused for a day. And that doesn't mean it will provide enough amps to start the engine. To find that out you need to run a load test. Step 1 is to take the battery out and get it load tested then go for there to check out other possibilities. Paul ========== At 12:07 PM 9/28/2009, you wrote: >I have a Rotax 912 UL engine on an Allegro 2000 LSA. Recently I have >had to replace my battery (12V 18Ah) because of it's inability to >crank the engine. Prior to replacing the battery I noticed my >combination Volt/Amp meter showed only 12 volts while flying. >Usually the voltmeter shows about 13.5 volts at start-up while the >engine is running on the ground and while flying. After replacing >the battery, and starting the engine the voltmeter returned to 13.5 >volts. However, when I began to close certain circuit breakers >engaging the front landing light, the two wing tip landing lights, >the two wing tip strobes, and the nav. lights I noticed the volt >meter dropping back each time I engaged one of the breakers until >finally the volt meter again was indicating only about 12 volts just >as before. I have a "no charge" red light in the battery charging >circuit that comes on if the battery is not being charged while the >engine is running. This light normally does not come on unless the >engine is at very low rpm ( aprx.1400 rpm). This is not normal for >my engine for my idle speed is set at 1800 rpm. > >I do not know why the voltage is dropping each time I close the >breaker for lights described above, or what may be causing the >voltage drop. I know I have a good battery, but I don't know if my >regulator is going bad, or if there may be aground some where, or >somthing else. Can anyone shed any light on what may be causing >this? The engine has only 255 hours on it and I have not had any >other problems with the engine. Any help would be greatly appreciated. > >Hugh G. McKay III >Allegro 2000 >Rotax 912 UL >N661WW > >hgmckay@bellsouth.net > > ________________________________ Message 6 _____________________________________ Time: 03:04:21 PM PST US From: Hugh MCKAY III Subject: Re: RotaxEngines-List: Re: Rotax 912 Charging Problem Ira: - My Rotax 912 UL installation manual shows on page 47 that the engine will p roduce 20 amps at 5000 rpm, and 18 amps at 4000 rpm at 13.5 volts DC. My to tal electrical load is 16.7 amps with a 100% load factor. The real load fac tor is more like 70% which gives an actual load of 11.7 amps. Where do you get the 16 amp maximum? Also I di not have this problem until just recently .. - Hugh- --- On Mon, 9/28/09, rampil wrote: From: rampil Subject: RotaxEngines-List: Re: Rotax 912 Charging Problem Hi Hugh, Remember that nasty lump on the rear end of your 912. That's the alternator.- It supplies electricity to run things on your airplane when the engine is going.- The alternator supplied as an integral part of the 912 can only supply 16 amps or so at 5500 rpm at 13.5volts.- When you turn on on enough electrical load, you are asking for more than the poor little thing can supply.- The regulator does not create power out of thin air, it only smooths out the voltage until it can't any more. If you don't shut off some of that electrical junk, the voltage will not be high enough to charge your battery. You can put on a new 40A alternator for about $800.- It will suck those extra amps right out of your propeller if you do. I would also recommend you read a bit about aircraft or automotive electrical systems. -------- Ira N224XS Read this topic online here: http://forums.matronics.com/viewtopic.php?p=265373#265373 le, List Admin. ________________________________ Message 7 _____________________________________ Time: 06:44:09 PM PST US From: Hugh MCKAY III Subject: Re: RotaxEngines-List: Re: Rotax 912 Charging Problem Pete: - What brand/type regulator did you have that failed? What type/brand did you replace it with? - Hugh McKay --- On Mon, 9/28/09, Pete Christensen wrote: From: Pete Christensen Subject: Re: RotaxEngines-List: Re: Rotax 912 Charging Problem Had the same problem with my Kitfox III/912. Asked the same questions. Repl aced the rectifier/regulator. Problem solved. - Pete - ----- Original Message ----- From: Hugh MCKAY III Sent: Monday, September 28, 2009 1:07 PM Subject: RotaxEngines-List: Re: Rotax 912 Charging Problem I have a Rotax 912 UL engine on an Allegro 2000 LSA. Recently I have had to replace my battery (12V 18Ah) because of it's inability to crank the engin e. Prior to replacing the battery I noticed my combination Volt/Amp meter s howed only 12 volts while flying. Usually the voltmeter shows about 13.5 vo lts at start-up while the engine is running on the ground and while flying. After replacing the battery, and starting the engine the voltmeter returne d to 13.5 volts. However, when I began to close certain circuit breakers en gaging the front landing light, the two wing tip landing lights, the two wi ng tip strobes, and the nav. lights I noticed the volt meter dropping back each time I engaged one of the breakers until finally the volt meter again was indicating only about 12 volts just as before. I have a "no charge" red light in the battery charging circuit that comes on if the battery is not being charged while the engine is running. This light normally does not come on unless the engine is at very low rpm ( aprx.1400 rpm). This is not normal for my engine for my idle speed is set at 1800 rpm. - I do not know why the voltage is dropping each time I close the breaker for lights described above, or what may be causing the voltage drop. I know I have a good battery, but I don't know if my regulator is going bad, or if t here may be aground some where, or somthing else. Can anyone shed any light on what may be causing this? The engine has only 255 hours on it and I hav e not had any other problems with the engine. Any help would be greatly app reciated. - Hugh G. 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