Rotax 915

Spank

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For those that have flown a Rotax 915, can you share your experience related to idle? I've heard that the engine runs rough on the ground while idling but that it is smooth otherwise in all other RPM's. I'm just curious what others are experiencing related to this.
 

Wisey01

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Not sure about the 915, but we dont let the 912 idle at 1800 rpm, as soon as its started the instructor bumps it up to 2200.

Cheers
 

Abid

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The gearbox of all the iS engines (912iS and 915iS) have zero degree dogs and thus chatter when at idle. The lowest idle should be 1800. You'd prefer 2000 as its starts to chatter less there and smooths out at higher RPM
 

Jungleman

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The gearbox of all the iS engines (912iS and 915iS) have zero degree dogs and thus chatter when at idle. The lowest idle should be 1800. You'd prefer 2000 as its starts to chatter less there and smooths out at higher RPM
Spank.
Just took delivery of a Magni M22 915 last month. Have flown 60 hrs in it. Absolutely love the engine and am blown away by its performance in our mountains compared to my 914.
The only issue I have is the lower rpm gearbox chatter. I find need to be at 2200 rpm to really eliminate it, which makes for alot of riding of brakes during taxi, & a bit more float during power off approaches.
At 1800 for initial pre rotation bystanders 30 meters away can hear the chatter.
Not sure how much damage its doing but maybe one of those quirks we have to live with.
I will at some stage talk to Rotax about it.
Pete
 

Jungleman

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Do you have bushwheels on it yet Pete.

wolfy
Hey Wolfy.
Yes got 26” Bushies on it and the new air shock nose assembly that I have been working on. Put 300 hours on the nose assy on various gyros since my last post on the Backcountry thread. So been busy. Its working out very well. Shot alot of video of the country I fly in so will edit & post in a couple of months when on a fire contract.
Back to the 915 as I said above the rate of climb blows me away. Weight for weight gyros & bushwheel configured where my 914 is doing 900 fpm the 915 is doing 1600, & lighter on fuel up to 1900fpm. So I am grinning like a racehorse eating thistles. 914 cruise is 73 kts, 915 87 kts (vne) Admittedly burning more fuel at those higher figures so range is the same. Sure is good to have that extra performance when needed though, or for when pushing into a 25kt head wind when home bound.
Pete
 

martin-av8r

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Interesting assembly setup

Rotax Alert Service Bulletin​


Inspection and re-torquing of oil spray nozzles for ROTAX® Engine Type 915 i A and 916 iSc B (Series)​


What's this about?​

Internal quality checks have shown that in isolated cases, one or more of the crankcase oil spray nozzles may not have been torqued to final tightening torque. The potential failure effect is a sudden engine stoppage with subsequent engine damage without warning in advance.​


Work performed iRMT rating required Labor credit Disassembly, inspection, reassembly, engine test run and logbook entry as per Chapter 3 (per engine) iRMT Maintenance Heavy* 14 h

 

DavePA11

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Wow - Disassembly of engine, inspection and reassembly. Heavy maintenance with 14 hours of labor by certified mechanic. Wonder what other issues just the disassembly and reassembly would cause.
 

Abid

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Wow - Disassembly of engine, inspection and reassembly. Heavy maintenance with 14 hours of labor by certified mechanic. Wonder what other issues just the disassembly and reassembly would cause.

Yup. Thankfully none of our customers engines (AR-1) seem to fall in this trap
 

martin-av8r

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Wow - Disassembly of engine, inspection and reassembly. Heavy maintenance with 14 hours of labor by certified mechanic. Wonder what other issues just the disassembly and reassembly would cause.
I think possibly for an aircraft engine the assembly and quality control need to be check a bit more
 

All_In

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For those that have flown a Rotax 915, can you share your experience related to idle? I've heard that the engine runs rough on the ground while idling but that it is smooth otherwise in all other RPM's. I'm just curious what others are experiencing related to this.
The two 915's I start do run rough when cold. I was taught by 2 CFI's to increase the RPM to 2,000/2,200 until the rattles go away.
It is the same thing and procedure with a 914. Only it has a choke and you need to adjust that as she warms up and increases RPM on the first start.

Once started in the morning and still warm she will idle at a higher RPM.

They like babbies. You have to burp them too before you check the oil level.
 

All_In

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Gyroplane 70Hrs, not sure over 10,000+ logged FW, 260+ ultralights, sailplane, hang-gliders
Interesting assembly setup

Rotax Alert Service Bulletin​


Inspection and re-torquing of oil spray nozzles for ROTAX® Engine Type 915 i A and 916 iSc B (Series)​


What's this about?​

Internal quality checks have shown that in isolated cases, one or more of the crankcase oil spray nozzles may not have been torqued to final tightening torque. The potential failure effect is a sudden engine stoppage with subsequent engine damage without warning in advance.​


Work performed iRMT rating required Labor credit Disassembly, inspection, reassembly, engine test run and logbook entry as per Chapter 3 (per engine) iRMT Maintenance Heavy* 14 h

This only applies to certain serial numbered 915's and 916's = by serial number.
 

Jungleman

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Wow - Disassembly of engine, inspection and reassembly. Heavy maintenance with 14 hours of labor by certified mechanic. Wonder what other issues just the disassembly and reassembly would cause.
Dave.
I have 3 Magni M22 Xtreme’s fitted with the 915 on the water and arriving NZ Jan. Two are affected by this bulletin.
Yes agree a real shame to have to pull down brand new engines to this extent, ( buggar ). One consolation though is its fantastic performance in the mountains.
Pete
 

DavePA11

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outside of this issue, the M22 with 915 and some of your tire/wheelmods is what I want for flying around the Rocky Mountains…
 
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