912 uls very hard time to start

H. Paul Shuch is a Light Sport Repairman with Maintenance ratings for airplanes, gliders, weight shift control, and powered parachutes, as well as an independent Rotax Maintenance Technician at the Heavy Maintenance level. He holds a PhD in Air Transportation Engineering from the University of California, and serves as Director of Maintenance for AvSport of Lock Haven.

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restlinbaum
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912 uls very hard time to start

Postby restlinbaum » Sat Jan 30, 2016 12:49 pm

I have a 2009 912uls with 1070 hrs. Both carbs have been serviced about 3 months ago. First flight of the day crank and crank but nothing, and if I add some choke it backfires nothing else. I have replaced the battery, and after it finally does start up works fine all day. Starts right up before every flight. It has never kicked back, and has always been a smooth running engine. Any suggestions?

Ray
Ray Estlinbaum, CFI-S

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FastEddieB
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Re: 912 uls very hard time to start

Postby FastEddieB » Sat Jan 30, 2016 1:28 pm

Have you replaced your ignition modules yet?
Fast Eddie B.
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3Dreaming
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Re: 912 uls very hard time to start

Postby 3Dreaming » Sat Jan 30, 2016 2:32 pm

When my first CT hit 200 hours I sent the carbs out for inspection and service. When they returned the airplane wouldn't start, and choke had no effect. Come to find out the starting carburetors (chokes) had been installed wrong. The left choke was on the right carb and vice versa.
It might be worth a look if the problem started with the carb service.

BrianL99
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Re: 912 uls very hard time to start

Postby BrianL99 » Sat Jan 30, 2016 2:43 pm

With 1000 hours, Fast Eddie probably identified the culprit.

Try the "ice test".

3Dreaming
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Re: 912 uls very hard time to start

Postby 3Dreaming » Sat Jan 30, 2016 3:24 pm

I was think it was the 2006-2007 engines that was having ignition module problems.

restlinbaum
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Re: 912 uls very hard time to start

Postby restlinbaum » Sat Jan 30, 2016 8:44 pm

I have not had them changed out, since there has never been a problem. I will have the carbs looked at first then move on to the modules, as it started after the carbs were serviced.
Ray Estlinbaum, CFI-S

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bstrachan
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Re: 912 uls very hard time to start

Postby bstrachan » Mon Jul 25, 2016 9:40 am

Try the "ice test".

What is the "ice test"???

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MrMorden
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Re: 912 uls very hard time to start

Postby MrMorden » Mon Jul 25, 2016 10:18 am

Take the top cowl off, put a bag of ice on the ignition modules for about 15 minutes. If the engine starts right up after that, you need both ignition modules replaced.
Andy Walker
Athens, GA
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bstrachan
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Re: 912 uls very hard time to start

Postby bstrachan » Mon Jul 25, 2016 10:22 am

Take the top cowl off, put a bag of ice on the ignition modules for about 15 minutes. If the engine starts right up after that, you need both ignition modules replaced.

Thx. So far, if I let the airplane sit for 30 minutes or so it starts up normally. I think I'll try the timing light test next time it won't start. That should show whether or not the ignition modules are faulty. Right now the problem is very intermittent.

comperini
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Re: 912 uls very hard time to start

Postby comperini » Mon Jan 29, 2018 10:43 am

Well, add me to the list of people with a 2007 engine, who's ignition modules failed. Thanks Roger Lee for the email advise.

Ice cube test confirmed the bad modules.

At almost $1000 a piece for those modules, I actually considered just installing an ice-maker right above the ignition modules. I think it would have been cheaper ;)
- Bob
Commercial pilot, CFI, DPE, Light Sport Repairman/Maintenance
http://www.sportpilotinstructor.com

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bstrachan
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Re: 912 uls very hard time to start

Postby bstrachan » Mon Jan 29, 2018 11:31 am

The 2006 -2007 ignition modules have a known starting problem.

These modules have two modes: start and run. There is no issue with the run mode, once the engine starts it will run forever. And if ONE start mode works, the engine will start and run. Only when both start modes fail (and they are intermittent) will the engine refuse to start.

I replaced ONE module a year or so ago, no more starting problems. There is no need to replace both and at $1,000 bucks a crack, well, enough said. All it takes is one module with a working start mode to get the engine going, and I haven't heard of or experienced any problems in the run mode.

Mike Busch recommends a "mag check" in flight, at cruise power. I think this is a good idea. It will show up problems that the runup mag check might miss.

YOUR problem may well be the chokes. My airplane started right up no problems, except when the intermittent module start mode came up bad in both modules. Then no amount of cranking would start the airplane, but if it sat for a few hours or days it would start right up again. I never experienced any backfiring when the engine refused to start. Yours sounds like carb problems to me.

comperini
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Re: 912 uls very hard time to start

Postby comperini » Mon Jan 29, 2018 11:47 am

I do think my problem was the modules. Choke, and carbs inspected and synced. Spark plugs new and gapped properly. Battery replaced (so I'm sure it was cranking fast enough), plus since replacing the modules, it does start right up now. Before, it had gotten to the point that I "might" start, or I might (probably) would just drain the battery with not even a sputter out of the engine.

Lockwood said one failed, and the other was "intermittent". It's kind of interesting... because for the past maybe 6 months or so, sometimes (maybe once per flight... maybe not at all), I'd get a 10 second or so time, where one mag just stopped working in flight. It's as if I turned it off. You could see it on the tach, and hear it in the engine. A few times on the ground, at idle, sure enough, one tach was inop. Often came back to life at a slightly higher than idle RPM. I was scratching my head, thinking I had a loose wire, or faulty ground. Checked everything, but found nothing.

So yea, I kind of think it was the ignitions afterall.

I understand there's a company overseas that claims to be able to fix these things for about half the price. Can't remember the website I found. I was a little skeptical of that, so I just bit the bullet, and fed the giant Rotax parts machine for new ones
- Bob
Commercial pilot, CFI, DPE, Light Sport Repairman/Maintenance
http://www.sportpilotinstructor.com

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bstrachan
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Re: 912 uls very hard time to start

Postby bstrachan » Mon Jan 29, 2018 12:03 pm

Whoa! I hadn't heard about RUN problems like yours, but it's not surprising. Those modules sit right up there on top of the engine where they get good and hot, and heat is the enemy of solid state devices.

The other thing that's bad is the way the modules are mounted. They are clamped tightly together which drastically reduces the surface area for heat rejection. When I replaced mine, I put a spacer in between to allow some airflow between the modules. Can't hurt.

Good luck and fly safe!

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David
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Re: 912 uls very hard time to start

Postby David » Mon Jan 29, 2018 7:48 pm

restlinbaum wrote:I have a 2009 912uls with 1070 hrs. Both carbs have been serviced about 3 months ago. First flight of the day crank and crank but nothing, and if I add some choke it backfires nothing else. I have replaced the battery, and after it finally does start up works fine all day. Starts right up before every flight. It has never kicked back, and has always been a smooth running engine. Any suggestions?

Ray


I wonder if you may have the start of a sprag clutch issue. View this video and see if the symptoms are similar. I did have a sprag clutch go bad at 400 hours

https://youtu.be/wOVwB5EmtRg
David
EAA 1434 Belfast ME
RV12 EAB - Maiden flight 8/30/12
David's RV12 http://www.rv12pilot.com

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ShawnM
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Re: 912 uls very hard time to start

Postby ShawnM » Fri Feb 09, 2018 8:37 am

restlinbaum wrote:I have a 2009 912uls with 1070 hrs. Both carbs have been serviced about 3 months ago. First flight of the day crank and crank but nothing, and if I add some choke it backfires nothing else. I have replaced the battery, and after it finally does start up works fine all day. Starts right up before every flight. It has never kicked back, and has always been a smooth running engine. Any suggestions?

Ray


My original 2007 ignition modules died the same way 2 years ago in January of 2016. I couldn't get it to start and throttle and choke adjustments only caused the engine to backfire. Luckily a hangar mate with a Sting let my mechanic swap my modules with his to verify and it started right up.

Back then you could buy a "ignition kit" that included both modules with soft start for $1000. Yes, both modules. They sold out like hotcakes as you can imagine and the "kit" was nowhere to be found anymore. I spent about an hour or so scouring the internet for this "kit" and found one on a shelf in the UK. Shipped to my door it was about $1100 USD. :mrgreen:

And as others have stated the 2006-02007 modules are known to have issues.

The company in the Netherlands that repairs the Ducati ignition modules is https://www.carmo.nl/ I dont remember the cost or turn around time but they can fix them.

Shawn


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