Matronics Email Lists :: View topic

Matronics Email Lists
Web Forum Interface to the Matronics Email Lists

Get Email Distribution Too! FAQ Search Memberlist Usergroups Register

Profile Log in to check your private messages Log in

Rough running 912S

Matronics Email Lists Forum Index -> Europa-List

View previous topic :: View next topic

Author Message

riddon(at)sent.com
Guest

Posted: Tue Mar 06, 2012 1:24 pm Post subject: Rough running 912S

My 912S hasn't run for almost 12 months. It started and ran well on ground runs. Test flight was OK although there was some 'plucking'. Since then I have flown three more times and am finding that the engine runs fine at full revs or climb settings but when I back off at the top of the climb, it splutters and coughs a bit and runs quite roughly as if it is missing a bit. Doesn't fill me with confidence. I have pulled the plugs and they seem fine, nice even grey colour, no oily plugs. Where do I look next?  



Richard Iddon



G-RIXS

klinefelter.kevin(at)gmai
Guest

Posted: Tue Mar 06, 2012 9:01 pm Post subject: Rough running 912S

Where do I look next?  

Carbs.

Kevin



On Mar 6, 2012, at 1:23 PM, Richard Iddon <riddon(at)sent.com> wrote:



 	  Quote: 	
		   

 

 My 912S hasn't run for almost 12 months. It started and ran well on ground runs. Test flight was OK although there was some 'plucking'. Since then I have flown three more times and am finding that the engine runs fine at full revs or climb settings but when I back off at the top of the climb, it splutters and coughs a bit and runs quite roughly as if it is missing a bit. Doesn't fill me with confidence. I have pulled the plugs and they seem fine, nice even grey colour, no oily plugs. Where do I look next?  

 

 Richard Iddon

 

 G-RIXS

dpark748(at)hotmail.co.uk
Guest

Posted: Wed Mar 07, 2012 12:11 am Post subject: Rough running 912S

Weather conditions. - carb ice?



Sent from my iPhone

On 7 Mar 2012, at 05:07, klinefelter.kevin(at)gmail.com wrote:



 	  Quote: 	
		   

 

 Where do I look next?  

 Carbs.

 Kevin

 

 On Mar 6, 2012, at 1:23 PM, Richard Iddon <riddon(at)sent.com> wrote:

 

> 

> 

> My 912S hasn't run for almost 12 months. It started and ran well on ground runs. Test flight was OK although there was some 'plucking'. Since then I have flown three more times and am finding that the engine runs fine at full revs or climb settings but when I back off at the top of the climb, it splutters and coughs a bit and runs quite roughly as if it is missing a bit. Doesn't fill me with confidence. I have pulled the plugs and they seem fine, nice even grey colour, no oily plugs. Where do I look next?  

> 

> Richard Iddon

> 

> G-RIXS

> 

> 

> 

>

Ivor Phillips

Joined: 16 Jan 2006
Posts: 253
Location: London UK

Posted: Wed Mar 07, 2012 12:32 am Post subject: Rough running 912S

Hi Richard

I would check the free movement of the throttle cables especially if they

have been under tension from the return springs for a year, Have you done a carb sinc? also fuel left in float chambers will evaporate and leave a gum like deposit

 in the bowl, its worth dropping the bowls for a check,

good luck

Ivor

On 7 March 2012 08:10, david park <dpark748(at)hotmail.co.uk (dpark748(at)hotmail.co.uk)> wrote:

 [quote]--> Europa-List message posted by: david park <dpark748(at)hotmail.co.uk (dpark748(at)hotmail.co.uk)>

  

 Weather conditions. - carb ice?

 

 Sent from my iPhone

 

 

 On 7 Mar 2012, at 05:07, klinefelter.kevin(at)gmail.com (klinefelter.kevin(at)gmail.com) wrote:

 

 > --> Europa-List message posted by: klinefelter.kevin(at)gmail.com (klinefelter.kevin(at)gmail.com)

 >

 > Where do I look next?

 > Carbs.

 > Kevin

 >

 > On Mar 6, 2012, at 1:23 PM, Richard Iddon <riddon(at)sent.com (riddon(at)sent.com)> wrote:

 >

 >> --> Europa-List message posted by: Richard Iddon <riddon(at)sent.com (riddon(at)sent.com)>

 >>

 >> My 912S hasn't run for almost 12 months. It started and ran well on ground runs. Test flight was OK although there was some 'plucking'. Since then I have flown three more times and am finding that the engine runs fine at full revs or climb settings but when I back off at the top of the climb, it splutters and coughs a bit and runs quite roughly as if it is missing a bit. Doesn't fill me with confidence. I have pulled the plugs and they seem fine, nice even grey colour, no oily plugs. Where do I look next?

  >>

 >> Richard Iddon

 >>

 >> G-RIXS

 >>

 >>

 >>

 >>

 >

 >

 >

 >

 >

 

 

 ===========

  target="_blank">http://www.matronics.com/Navigator?Europa-List

 ===========

 http://forums.matronics.com

 ===========

 le, List Admin.

 ="_blank">http://www.matronics.com/contribution

 ===========

 

 

 

 



[b]

rlborger(at)mac.com
Guest

Posted: Wed Mar 07, 2012 8:26 am Post subject: Rough running 912S

Richard,



I would suggest you sign up for and post this question to the Rotax-list(at)matronics.com as there is some good Rotax specific knowledge there.  Perhaps there's someone who has had the same experience.



Blue skies & tailwinds,

Bob Borger

Europa XS Tri, Rotax 914, Airmaster C/S Prop.

Little Toot Sport Biplane, Lycoming Thunderbolt AEIO-320 EXP

3705 Lynchburg Dr.

Corinth, TX  76208-5331

Cel: 817-992-1117

rlborger(at)mac.com



On Mar 6, 2012, at 3:23 PM, Richard Iddon wrote:






My 912S hasn't run for almost 12 months. It started and ran well on ground runs. Test flight was OK although there was some 'plucking'. Since then I have flown three more times and am finding that the engine runs fine at full revs or climb settings but when I back off at the top of the climb, it splutters and coughs a bit and runs quite roughly as if it is missing a bit. Doesn't fill me with confidence. I have pulled the plugs and they seem fine, nice even grey colour, no oily plugs. Where do I look next?  



Richard Iddon



G-RIXS

pete(at)lawless.info
Guest

Posted: Wed Mar 07, 2012 8:51 am Post subject: Rough running 912S

Richard



Have you got the little plastic pipes from the carbs connected into the air

box?



I have had exactly the same symptoms on my 912 when I left the pipes

unconnected after working on the aeroplane.  Good in the climb and missing

and rough when I pulled the power back.



Regards



Pete



--

riddon(at)sent.com
Guest

Posted: Wed Mar 07, 2012 11:47 am Post subject: Rough running 912S

Hi Guys. 

Fuel was drained before layup, bowls dropped and cleaned out. Engine was left with carbs at full throttle, i.e. minimum tension on springs. Carbs have been re-balanced before test flight. Ran perfectly on the ground. 

I have rotax permanent carb heaters fitted so that should eliminate possibility of ice, (I hope!) although humidity was very high for this particular flight. I had to wait for fog to clear before flight and temperature and dew point were both 7deg. 

I guess I will pull the carbs off, check the sockets and diaphragms, ensure float bowl vent pipes are OK. Incidentally, I replaced all the fuel pipes, including the vent pipes, at layup. 

Will report back if progress is made. 

Richard Iddon. 

On 7 Mar 2012, at 08:31, PHILLIPS I wrote:

 	  Quote: 	
		   Hi Richard

 I would check the free movement of the throttle cables especially if they

 have been under tension from the return springs for a year, Have you done a carb sinc? also fuel left in float chambers will evaporate and leave a gum like deposit

 in the bowl, its worth dropping the bowls for a check,

 good luck

 Ivor

 On 7 March 2012 08:10, david park <dpark748(at)hotmail.co.uk> wrote:

 Weather conditions. - carb ice?

 Sent from my iPhone

 On 7 Mar 2012, at 05:07, klinefelter.kevin(at)gmail.com wrote:

 > 

 >

 > Where do I look next?

 > Carbs.

 > Kevin

 >

 > On Mar 6, 2012, at 1:23 PM, Richard Iddon <riddon(at)sent.com> wrote:

 >

 >> 

 >>

 >> My 912S hasn't run for almost 12 months. It started and ran well on ground runs. Test flight was OK although there was some 'plucking'. Since then I have flown three more times and am finding that the engine runs fine at full revs or climb settings but when I back off at the top of the climb, it splutters and coughs a bit and runs quite roughly as if it is missing a bit. Doesn't fill me with confidence. I have pulled the plugs and they seem fine, nice even grey colour, no oily plugs. Where do I look next?

 >>

 >> Richard Iddon

 >>

 >> G-RIXS

 >>

 >>

 >>

 >>

 >

 >

 >

 >

 >

 ===========

 target="_blank">http://www.matronics.com/Navigator?Europa-List

 ===========

 http://forums.matronics.com

 ===========

 le, List Admin.

 ="_blank">http://www.matronics.com/contribution

 ===========

 http://www.matronics.com/Navigator?Europa-List

 http://forums.matronics.com

 http://www.matronics.com/contribution

rlborger(at)mac.com
Guest

Posted: Wed Mar 07, 2012 4:39 pm Post subject: Rough running 912S

Richard,



When you have the carbs off, check the condition of the needles and orifices.  Ensure there is nothing providing a partial blockage to the orifice on either carb.



Blue skies & tailwinds,

Bob Borger

Europa XS Tri, Rotax 914, Airmaster C/S Prop.

Little Toot Sport Biplane, Lycoming Thunderbolt AEIO-320 EXP

3705 Lynchburg Dr.

Corinth, TX  76208-5331

Cel: 817-992-1117

rlborger(at)mac.com



On Mar 7, 2012, at 1:46 PM, Richard Iddon wrote:






Hi Guys. 



Fuel was drained before layup, bowls dropped and cleaned out. Engine was left with carbs at full throttle, i.e. minimum tension on springs. Carbs have been re-balanced before test flight. Ran perfectly on the ground. 



I have rotax permanent carb heaters fitted so that should eliminate possibility of ice, (I hope!) although humidity was very high for this particular flight. I had to wait for fog to clear before flight and temperature and dew point were both 7deg. 



I guess I will pull the carbs off, check the sockets and diaphragms, ensure float bowl vent pipes are OK. Incidentally, I replaced all the fuel pipes, including the vent pipes, at layup. 



Will report back if progress is made. 



Richard Iddon.

budyerly(at)msn.com
Guest

Posted: Wed Mar 07, 2012 4:39 pm Post subject: Rough running 912S

<?xml:namespace prefix="v" /><?xml:namespace prefix="o" /><![endif]-->  Richard,

 There are many things which can cause this problem and you are on the right  track.  Rarely does a new Rotax need any tuning, but we tune them anyway  here at Custom Flight, as the factory doesn't quite center speck the engine to  what I call sewing machine smooth... In fact on the last three engines, my  fillings hurt from the factory tune.  Not rough, but not right. 

  

 Please check your throttle cables are working together.  I will not  cut the cables as the slightest of binding causes a draggy cable.  Some use  solid cables, I have a bird flying 10 years on the same stock cables and it  still works like a charm.  Check the plugs are all basically the same with  no heavy black soot or white hot deposits.  A nice grayish brown look is  right.

  

 Next is the carb balance.    We use dual manometers  supplied by Rotax and mechanically set the idle stops using the maintenance  manual procedures, then we pneumatically balance the carbs until each carb is  exactly the same pressure using the Rotax tuning method.  Reconnect the  crossover tube and all should be smooth up to 4000 RPM.  If you still have  a rough spot, move the needles to the third position.. At full throttle,  and all is well, and when at 3500 or below it runs rough on the ground please  look at your carb mixture.  For operations at sea level to 1500 feet field  elevations we have found setting the carb needle at the third position for both  carbs does best at clearing this rough area. The factory sets one carb normally  at position 2 on the needle and the other on three.   This third  position is a bit richer and at part load we get better running at part  throttle.   If you have EGT, note the changes on your EGT from side to  side..  You can tell if it is too rich at 4000 RPM if you pull the  choke out 1/4 inch and the engine runs rough and wants to die as (believe it or  not) the enrichening circuit (we call the choke) only works at near idle  conditions and actually leans at 4000 RPM.  If the engine smoothly  increases or steady's, then your as rich as you want.  I didn't  believe this until Kerry at Lockwood showed me on our 914.  Pretty  neat.

  

 If your mag drop is 300 or slightly more, you have a mixture problem.   I know, it sounds stupid, but it is true.  You may be a bit lean and moving  the needles to a richer setting may be necessary.  I'm sure you're happy to  note I have you taking the carbs apart a lot.  But once set, I never have  touched mine in three years.

  

 The carb heaters are not the problem, but check for an intake manifold leak  at the rubber gaskets as you said.  Of course it will be easy to tell if  you have a manifold leak if you are using the dual Rotax carb balancing tool  with the gauges.  I do not use the electric models.  Close the in line  valves to get the needles reasonably steady.  Good advice has been given to  watching your intake plenum coming loose and checking for leaks as it causes  roughness in the lower 4-5000 RPM area....  .

  

 Do clean the jets after the engine has sat for a long while for sure and  run the required check of the float bowl plunger so that it shuts off  well.  Clean with solvent and low pressure air, not a piece of safety wire  which will scratch the jets and change your settings.  Cleanliness in your  tank and fuel lines is a must.  I don't even start an engine until flushing  the tank at least three times with fuel, changing the filters in between and  again before test flying.  

  

 If she's still running rough look at ignition.  Plugs should be clean,  so check your color and compare left side to right.

 Hook a timing light to each spark plug lead and idle the engine using a  helper to keep you safe.  Watch the light and look for a miss in a  cylinder.  You may have a bad coil, unlikely in a new engine, but it has  happened.

  

 Finally, if you have a fixed pitch prop (especially a Warp Drive) and you  throttle back in flight above 80 KIAS, the prop, when windmilling (being driven  by the wind) from high speed sets up a nasty noise and bit of  vibration.  It is just like compression braking, and the 912S and gearbox  combo with this prop will tend to vibrate.  This is the gear box lash and  turbulence off the prop making the nasty noise and bit of vibration.  This  is quite startling to the new Europa passenger.    The Airmaster  AP332 will also set up a vibration when compression braking in a rapid descent  by moving the prop from cruise to climb at low power, as the blade change to a  flatter setting sets up a bit of turbulence... When doing a speed run at cruise  of about 140 KIAS, I rarely move the prop to climb with the power set below 31  inches because it scares the customers with the sound change and  vibration.  The comment is usually "is it supposed to do that!".

  

 Keep us posted.  You're on the right track.

  

 Regards,

 Bud Yerly

Custom Flight Creations, Inc.

www.customflightcreations.com

(813)  653-4989

  

  

  

  

 [quote]   ---

FTower(at)cbmove.com
Guest

Posted: Thu Mar 08, 2012 11:59 am Post subject: Rough running 912S

Bud- Irony that your great tuning advice comes on the same day as the forwarding of the Pipistrel item on their being selected as the launch company for the 912 Injection S engine!

 

                                                Best, 

                                               Fred



________________________________



From: owner-europa-list-server(at)matronics.com on behalf of Bud Yerly

Sent: Wed 3/7/2012 7:38 PM

To: europa-list(at)matronics.com

Subject: Re: Rough running 912S

Richard,

There are many things which can cause this problem and you are on the right track.  Rarely does a new Rotax need any tuning, but we tune them anyway here at Custom Flight, as the factory doesn't quite center speck the engine to what I call sewing machine smooth... In fact on the last three engines, my fillings hurt from the factory tune.  Not rough, but not right. 

 

Please check your throttle cables are working together.  I will not cut the cables as the slightest of binding causes a draggy cable.  Some use solid cables, I have a bird flying 10 years on the same stock cables and it still works like a charm.  Check the plugs are all basically the same with no heavy black soot or white hot deposits.  A nice grayish brown look is right.

 

Next is the carb balance.    We use dual manometers supplied by Rotax and mechanically set the idle stops using the maintenance manual procedures, then we pneumatically balance the carbs until each carb is exactly the same pressure using the Rotax tuning method.  Reconnect the crossover tube and all should be smooth up to 4000 RPM.  If you still have a rough spot, move the needles to the third position.. At full throttle, and all is well, and when at 3500 or below it runs rough on the ground please look at your carb mixture.  For operations at sea level to 1500 feet field elevations we have found setting the carb needle at the third position for both carbs does best at clearing this rough area. The factory sets one carb normally at position 2 on the needle and the other on three.   This third position is a bit richer and at part load we get better running at part throttle.   If you have EGT, note the changes on your EGT from side to side..  You can tell if it is too rich at 4000 RPM if you pull the choke out 1/4 inch and the engine runs rough and wants to die as (believe it or not) the enrichening circuit (we call the choke) only works at near idle conditions and actually leans at 4000 RPM.  If the engine smoothly increases or steady's, then your as rich as you want.  I didn't believe this until Kerry at Lockwood showed me on our 914.  Pretty neat.

 

If your mag drop is 300 or slightly more, you have a mixture problem.  I know, it sounds stupid, but it is true.  You may be a bit lean and moving the needles to a richer setting may be necessary.  I'm sure you're happy to note I have you taking the carbs apart a lot.  But once set, I never have touched mine in three years.

 

The carb heaters are not the problem, but check for an intake manifold leak at the rubber gaskets as you said.  Of course it will be easy to tell if you have a manifold leak if you are using the dual Rotax carb balancing tool with the gauges.  I do not use the electric models.  Close the in line valves to get the needles reasonably steady.  Good advice has been given to watching your intake plenum coming loose and checking for leaks as it causes roughness in the lower 4-5000 RPM area....  .

 

Do clean the jets after the engine has sat for a long while for sure and run the required check of the float bowl plunger so that it shuts off well.  Clean with solvent and low pressure air, not a piece of safety wire which will scratch the jets and change your settings.  Cleanliness in your tank and fuel lines is a must.  I don't even start an engine until flushing the tank at least three times with fuel, changing the filters in between and again before test flying.  

 

If she's still running rough look at ignition.  Plugs should be clean, so check your color and compare left side to right.

Hook a timing light to each spark plug lead and idle the engine using a helper to keep you safe.  Watch the light and look for a miss in a cylinder.  You may have a bad coil, unlikely in a new engine, but it has happened.

 

Finally, if you have a fixed pitch prop (especially a Warp Drive) and you throttle back in flight above 80 KIAS, the prop, when windmilling (being driven by the wind) from high speed sets up a nasty noise and bit of vibration.  It is just like compression braking, and the 912S and gearbox combo with this prop will tend to vibrate.  This is the gear box lash and turbulence off the prop making the nasty noise and bit of vibration.  This is quite startling to the new Europa passenger.    The Airmaster AP332 will also set up a vibration when compression braking in a rapid descent by moving the prop from cruise to climb at low power, as the blade change to a flatter setting sets up a bit of turbulence... When doing a speed run at cruise of about 140 KIAS, I rarely move the prop to climb with the power set below 31 inches because it scares the customers with the sound change and vibration.  The comment is usually "is it supposed to do that!".

 

Keep us posted.  You're on the right track.

 

Regards,

Bud Yerly

Custom Flight Creations, Inc.

www.customflightcreations.com <http://www.customflightcreations.com/> 

(813) 653-4989

 

 

 

 



	---

Display posts from previous:

	Matronics Email Lists Forum Index -> Europa-List	All times are GMT - 8 Hours
Page 1 of 1

Jump to:

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum