Repairing my airplane; how to solve Rotax 912 ULS engine vibrations and more - S03 E01

The closure of my home airport, due to yet another COVID lockdown, opened up the possibilities to give my airplane some TLC. Not that my TL Ultralight TL-96 Star needed a lot of maintenance, but there were some little things and somewhat bigger ones, to take care off. See full description...
I still had to fix the outlet port of the exhaust pipe heat exchanger, that feeds hot air into the cabin (my cabin heating system). That pipe was almost completely rotten away and temporary fixed by the previous owner. So I asked a pilot friend to weld a new steel pipe onto the existing heat exchanger, which worked out pretty well.
A second thing on my to-do list was to replace all the existing spark plugs of my Rotax 912 ULS, to shorten the spark plug leads and to re-attach the spark plug caps to the fresh conducting core of the shortened leads. I've been told by many Rotax mechanics that this could be a possible solution to engine vibration at low RPM (low idle). Despite all my careful work, it wasn't.
So now I'm on the path of carburetor overhaul. I de-installed both BING 64 carburetors from the engine and brought them to another pilot friend, who has a lot of experience in overhauling these types of carbs. Both carburetors will be disassembled, cleaned with an ultrasonic bath, most parts will be replaced with new ones, they get assembled again and installed and configured on my engine. All in all a lot of work.
Hopefully this wil solve the engine vibration problem. If not, it's on to a gearbox overhaul next...
FlightChops' New Year's 2021 video:
• 100s of YOUR Flying St...
#aircraft #rotax #maintenance
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DISCLAIMER
Ever since I received my pilot license, I shared my passion for aviation with a lot (and I mean a lot!) of passengers! Because I enjoy sharing my aviation passion so much, I would like to share it with the rest of the world too! But since taking on 7 billion people as my passenger isn't really practical, sharing my passion via KZbin is... ;)
Where a lot of aviation channels on KZbin focus on General Aviation at the west side of the Atlantic, my channel focuses on Light Sport Aviation in Europe, primarily Holland and Germany. Light Sport Aircraft are also known as 'Microlight Aircraft' or 'Ultralight Aircraft'.
The reason I make these videos is to exchange aviation stories and learn and improve by sharing. And because I love to share!

[@DutchAviationBlog]

Man, owning a plane is a lot of work! All worth it in the end though, especially with such a beautiful aircraft as the TL96! Let’s hope we can get back to flying around Friesland sooner than later.. At least the time on the ground was well spend with trying to solve some issues with regards to the engine. Great video (as always of course 😉)

[@ForFunFlyer]

Thanks Cpt. Niels! 👍🏻 Looking fwd to the next flight very, very much! 😎

[@GolfFoxtrot22]

I definitely know that feeling. Thanks for showing us under the cowling again.

[@ForFunFlyer]

You're welcome! 👍🏻

[@rixtrix11]

The short clip was great, Congrats on the restoration it's abeautiful plane and on getting licensed! Love the technical stuff, too.

[@ForFunFlyer]

Thanks! 👍🏻

[@PrivatePilotFlightVlogs]

Great update video to see what you are doing. You have some talented friends too!

[@ForFunFlyer]

Yes, they are just as talented as they are awesome to hang out with! 💪🏻

[@GolfFoxtrot22]

I enjoyed that, I liked you 'flightchops' clip. Your just being a tease with leaving the carb install till the next video. Being an engineering geek, I quite like this type of content.

[@ForFunFlyer]

Haha, sorry for the cliff hanger 😋 The overhaul won't be documented, but the install, dialing in and syncing of them will be 👌🏻

[@GolfFoxtrot22]

@@ForFunFlyer Woohoo.

[@mikaelwallinder8866]

Hello Jolmer! I do not mind the technical stuff, please show more :-) all the best from Sweden!

[@ForFunFlyer]

Wilco and thanks! 👍🏻

[@dutchygirl]

If I remember well, I came here while you were posting tech stuff and found that interesting, so boring?! Your contribution to Steve's call looked great. Those were 4 well spend hours. Now, hopefully your airport will open up soon again and you'll have your aircraft in one peace by that time ;-) In the meantime, keep her warm!

[@ForFunFlyer]

Thanks! Yeah, I already documented some tech stuff on the channel 😋 Hopefully she's in one piece again soon and I'll get airborne again 👍🏻

[@KevinWolters]

Nice video Jolmer! Hope the engine vibrations will be gone after some tlc by Oedze! Keep up the good work and I hope we can fly again soon! Cheers!

[@ForFunFlyer]

Thanks! 👍🏻 Yes, hopefully this is it. If not, I'm in for a gearbox overhaul too 🙈

[@RealGoldRealWealth]

Jolmer Happy New Year to you and your wife. Nice 30 sec video.... a picture is worth a thousand words. A video many thousands! Many micro sized posters are just as important as the more well known ones. They put their heart and soul into making a recording of their love of flying. And it's all good, perhaps not as "professional looking," but authentic none-the-less and therefore valuable to us as a community, no matter what our preference for the type or aspect of aviation. For the heating muff ... stainless steel an option? And I'm sure you checked out micro holes in the exhaust stack to preclude any CO2 from entering cabin hot air duct.

[@ForFunFlyer]

I couldn't agree more, you're absolutely right! 👍🏻 Yes, I inspected the exhaust pipe carefully and all is OK. I do decided to install a CO alarm in the cabin, just in case something would leak. But I'm pretty confident that this repair is OK 😉 Thanks for watching! 👍🏻

[@hirnklempner]

Good luck! Hope it will work well when the epidemic and the weather get better! 😀 I'm afraid you will have plenty of time to fix it. 😬🍀

[@ForFunFlyer]

Well, our airport will reopen again on only saturdays, for home based aircraft only 👍🏻 So I hope to fix the low idle vibration soon. Hopefully I don't need to overhaul the gearbox too, fingers crossed... 🤞🏻

[@hirnklempner]

@@ForFunFlyer 🕯😀

[@johnling4299]

You have a new subscriber, Just over from Giles Fowler , Great to join you.

[@ForFunFlyer]

Ah, thanks! Welcome! 👍🏻

[@JodelFlyer]

Not boring us with technical stuff Jolmer as it is interesting to see and hear what you are doing. I thought your Flight Chops submission was very good. I know it is not easy to restrict yourself to 30 seconds of video and although he used mine some of my narrative came over the top of a different clip? Having said that he did try hard with the project which seems to be an annual thing with his channel. Looking forward to your next installment. Take care and stay safe.

[@ForFunFlyer]

Yes, he had a couple of long days of editing and did a great job with the video 👌🏻 Maybe I'm there next year? 😉 Thanks for watching! 👍🏻

[@JodelFlyer]

ForFunFlyer - I did mean to say Jolmer that at least you are allowed onto the airfield. I know of at least one in the UK where the gates are closed to the airfield and no one can get to their aircraft.

[@ForFunFlyer]

@@JodelFlyer Ouch, that's even worse... 🤔😕

[@lifefromanotherangle4774]

Hi. We had severe engine vibrations even after certified mechanics did service on engine and balanced the carb. Mechanics said proppellers are not balanced properly, and we thought it is gearbox. As a engineer first thing I did was weld the air mixture senzor (50UsD on ebay). You need to measure main engine parameters, mixture is first on the list. It was way too rich in all regime IDLE, MID FULL. We found feew loose screw on choke, we put epoxy on all machined canals on the exterior. We spent time to lean and balance idle jets on booth carbs, adjusted needle jet to more lean setting. Now it works like clock. Very important: you should never have leaner mixture than 14:1 as can result in knocking during heavy engine load and damagingthe engine.

[@ForFunFlyer]

This was also on a Rotax 912 engine? I never touched the mixture by adjusting the jet needle or screws. Normally its factory set and good to go. What wanders over time is the sync between the two carbs or the (first signs of) failure of one of the ignition modules. Happy to hear you solved the issue 👍🏻

[@lifefromanotherangle4774]

@ForFunFlyer same 912 100HP. from vibrations and aging screws, o ring etc can losen. Mixture sensor removes guess work and points to the problem

[@jurisbruzuks4288]

To the attention of Rotax aircraft engine users! This engine worked for 210 hours and fell apart during the flight in the air. The reason was oil starvation of one crankshaft journal. A preliminary inspection showed that the problem was from the very beginning and the connecting rod at least received lubrication from the crankcase. But it wasn't enough and the connecting rod with the bushing, having received a large gap, collapsed. From beginning of operation with a warm engine, when the speed was reduced to a minimum, the temperature and oil pressure began to rise. By adding speed, everything returned to normal. The company ROTAX does not recognize their marriages!

[@flyingkub]

looks like we are in the same state. We can not fly either , so, I too have been doing maintenance on my aircraft (new reduction belt, plugs, fuel filter, tailwheel and lubrication / inspection) but I did not get any useable video. I also sent Flight Chops a video that must have been in the same file as yours and did not get used (that said, he did not promis to use it, so I had no expectation. I am just a micro channel and he had good stuff from others). I hope you have fixed your vibration problem, don't forget to get the carbs ballanced as that can be the problem with the Rotax 912 engines.

[@ForFunFlyer]

I heard from Steve that he had to dissapoint a lot of people, not including their video. It must have been a lot to handle. Yes, fingers crossed the low idle vibration is gone after this. Else I'm in for a gearbox overhaul too 🙈 I'm familiar with syncing the carbs. Thst friend who is overhauling my carbs is quite the expert in that too 😉

[@flyingkub]

@@ForFunFlyer I hope it isn't the gearbox but have been told that they some times can be re-shimmed.

[@ForFunFlyer]

@@flyingkub Oh yes, the gearbox is doable. Already did that on my previous plane. But first things first; carbs overhaul and testing. Then go from there...

[@larrymangold1048]

There is a notice from Rotax to upgrade/replace the carburetor floats. Was that an issue you discovered?

[@ForFunFlyer]

Not on this occassion. A year after this video was published, the float issue appeared. Now, all is OK 👍🏻

[@Joelmelanie]

loved it

[@ForFunFlyer]

Thanks!

[@davidecolley]

It sounds like your carbs need balancing and that should fix the rough running vibration. Also you shouldn't have shortened your plug leads, they are a set length.

[@ForFunFlyer]

Really? Didn't know that about the leads. They're all shortened at the same amount, so that should be better than all different lengths? Oh, and the carbs were balanced a couple months back, so that can't be the cause this time, I think. Thanks for your comment 👍🏻

[@jonrau5988]

I really hope you can find the cause of the engine roughness. Better to find it on the ground than have it quit in the air.

[@ForFunFlyer]

Yeah, me too! If this isn't the solution, it's on to a gearbox overhaul... 🙈😋

[@chrisarvin1715]

Carburetors need to be synchronized

[@ForFunFlyer]

Did that already, no joy. This is something else, perhaps solved after carb overhaul...

[@lawlorhanson]

Maybe gearbox

[@ForFunFlyer]

Yes, that's on my list too. But since my carbs were never serviced, I decided to do that anyway and see if it fixes anything. If not, it's on to a gearbox overhaul too 😉 Thanks for watching! 👍🏻