Today's Message Index:
----------------------
1. 04:54 AM - 912UL turning backwards on shutdown (Catz631@aol.com)
2. 05:38 AM - Re: 912UL turning backwards on shutdown (dave)
3. 05:41 AM - Re: 912UL turning backwards on shutdown (Dave Fisher)
4. 05:44 AM - Re: 912UL turning backwards on shutdown (Richard Girard)
5. 06:30 AM - Re: 912UL turning backwards on shutdown (dave)
6. 06:36 AM - Re: 912UL turning backwards on shutdown (Roger Lee)
7. 06:41 AM - Re: 912 oil purge proceedure (Roger Lee)
8. 06:48 AM - Re: 912UL turning backwards on shutdown (Noel Loveys)
9. 07:12 AM - Re: 912UL turning backwards on shutdown (Scott DeMeyer)
10. 07:21 AM - Re: Re: 912UL turning backwards on shutdown (Noel Loveys)
11. 10:08 AM - Re: Re: 912UL turning backwards on shutdown (Noel Loveys)
12. 10:23 AM - Re: 912UL turning backwards on shutdown (Noel Loveys)
13. 11:13 AM - Re: 912UL turning backwards on shutdown (rparigoris)
14. 12:02 PM - Re: 912UL turning backwards on shutdown (Roger Lee)
Message 1
| INDEX | Back to Main INDEX |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | 912UL turning backwards on shutdown |
Well, my old nemesis is back with a vengeance! Yesterday was a very hot
(96degree) , muggy,lousy,typical Florida summer day. So why not go fly. I did
and after shutting my engine down it slung itself backwards at least 5-10
engine revolutions (not blades) If I would have turned the mags back on, and
the jugs didn't blow I betI I could have backed into my parking spot! Everyone
that saw this was amazed. They have never seen an engine do this. It has
done this too me before about 5 times but never turned backwards that many
revolutions.
Now I do realize that I am the ONLY person in the world that has had this
problem (verified by calls to tech reps at Lockwood and LEAF) but I would
like this to stop. It's beginning to give me the RA (red ass)
I only mention this again on this forum to see if some of you gurus agree
with me on the procedure I will follow from here. I plan on getting an oil
sample today and sending it off for analysis for metal to see if there is any
cam damage from collapsed lifters. As I understand it turning the engine
backwards could ingest air into the lifters thus causing one or more to
collapse thus causing scuffing of the cam lobes (ie:metal)
I have performed the valve lifter check after each of these events and at
no time in the past have the clearances been greater than 20 thousands which
according to the bulletin would indicate air in the lifters. The oil filter
has always been free of metal also.
After this last event at an outlying field, I restarted the engine, the
oil pressure fluctuated a little bit at idle (as it always does since I have
had the airplane) normal rpm produced steady oil pressure so I flew the
aircraft back home (10 minutes) Today I might do another check for air in the
lifters but I am sure if any was there, it is gone due to the 10-15 minutes of
flight time home.
I believe the major causes of this problem are, old premium fuel (over30
days as I was on vacation) high outside temps and the fixed engine ignition
timing is off somewhat. I had added octane booster to the fuel as this has
helped in the past but probably not added enough.
I have borescopped the engine cylinders and they seem relatively free of
carbon (250 hrstt engine)
Any ideas?
I am running a Warp drive prop. I have even thought of going back to the
Kiev prop. It is about a pound lighter than the Warp. It,s momentum would be
less than the Warp. Maybe that would do it. Mystery!
Thanks,
Dick Maddux
Kitfox 4
Milton,Fl
Message 2
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: 912UL turning backwards on shutdown |
Dick,
Are you using avgas or auto premium ?
Sounds like pre ignition-- since you likley do not have a mixtue cut off try shutting
off the fuel vakve at shut down.
912 UL will run fine on auto regular 87 grade --with or without ethanol.
Acutally you might want to run a tank of ethanol regular gas through it and see
if that helps.
Although many armchair captains will say bal bla bla about ethanol Rtoax does
infact recoment the use of it up to 10%.
Also who says that premium is always premium gas at the pumps. I VERY rarely use
premium if ever on Rotax 2 stroke and 912 UL . 912 S yes preium auto fuel
only. NO avgas.
Just in from 1.5 flight on ethanol gas -- I am over 1000 hours onethanl gas no
personally without a gitch so far. :)
--------
Rotax Dealer, Ontario Canada
http://www.cfisher.com/
Awesome *New Forum *
http://rotaxaircraft.com/forum/
Realtime Kitfox movies to separate the internet chatter from the truth
http://www.youtube.com/profile_videos?user=kitfoxflyer
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=299344#299344
Message 3
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: 912UL turning backwards on shutdown |
Dick,
Are you using avgas or auto premium ?
Sounds like pre ignition-- since you likley do not have a mixtue cut off
try shutting off the fuel vakve at shut down.
912 UL will run fine on auto regular 87 grade --with or without
ethanol.
Acutally you might want to run a tank of ethanol regular gas through it
and see if that helps.
Although many armchair captains will say bal bla bla about ethanol
Rtoax does infact recoment the use of it up to 10%.
Also who says that premium is always premium gas at the pumps. I VERY
rarely use premium if ever on Rotax 2 stroke and 912 UL . 912 S yes
preium auto fuel only. NO avgas.
Just in from 1.5 flight on ethanol gas -- I am over 1000 hours onethanl
gas no personally without a gitch so far. :)
----- Original Message -----
From: Catz631@aol.com
To: rotaxengines-list@matronics.com
Sent: Sunday, May 30, 2010 7:54 AM
Subject: RotaxEngines-List: 912UL turning backwards on shutdown
Well, my old nemesis is back with a vengeance! Yesterday was a very
hot (96degree) , muggy,lousy,typical Florida summer day. So why not go
fly. I did and after shutting my engine down it slung itself backwards
at least 5-10 engine revolutions (not blades) If I would have turned the
mags back on, and the jugs didn't blow I betI I could have backed into
my parking spot! Everyone that saw this was amazed. They have never seen
an engine do this. It has done this too me before about 5 times but
never turned backwards that many revolutions.
Now I do realize that I am the ONLY person in the world that has had
this problem (verified by calls to tech reps at Lockwood and LEAF) but I
would like this to stop. It's beginning to give me the RA (red ass)
I only mention this again on this forum to see if some of you gurus
agree with me on the procedure I will follow from here. I plan on
getting an oil sample today and sending it off for analysis for metal to
see if there is any cam damage from collapsed lifters. As I understand
it turning the engine backwards could ingest air into the lifters thus
causing one or more to collapse thus causing scuffing of the cam lobes
(ie:metal)
I have performed the valve lifter check after each of these events
and at no time in the past have the clearances been greater than 20
thousands which according to the bulletin would indicate air in the
lifters. The oil filter has always been free of metal also.
After this last event at an outlying field, I restarted the engine,
the oil pressure fluctuated a little bit at idle (as it always does
since I have had the airplane) normal rpm produced steady oil pressure
so I flew the aircraft back home (10 minutes) Today I might do another
check for air in the lifters but I am sure if any was there, it is gone
due to the 10-15 minutes of flight time home.
I believe the major causes of this problem are, old premium fuel
(over30 days as I was on vacation) high outside temps and the fixed
engine ignition timing is off somewhat. I had added octane booster to
the fuel as this has helped in the past but probably not added enough.
I have borescopped the engine cylinders and they seem relatively free
of carbon (250 hrstt engine)
Any ideas?
I am running a Warp drive prop. I have even thought of going back to
the Kiev prop. It is about a pound lighter than the Warp. It,s momentum
would be less than the Warp. Maybe that would do it. Mystery!
Thanks,
Dick Maddux
Kitfox 4
Milton,Fl
Message 4
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: 912UL turning backwards on shutdown |
Dick, Try dropping your idle speed so that you have to set it manually. That
way you can be sure the throttle is completely closed when you shut off the
mags. Check for fuel leaking into the engine through the starting
carburetor, too. For the weather you're having you might want to try one
range colder spark plug, also. Have you looked into the combustion chamber
with a bore scope to make sure there isn't any sort of carbon build up that
could cause detonation? Be sure and burp your engine after one of these run
on events.
VW's (the old air cooled models) started doing this when they were leaned
out for emissions control in the late 60's. It was solved by putting a
solenoid and plunger over the main jet that choked off the fuel supply
completely. When the solenoid failed ("Volkswagen does it again" was their
advertising slogan at the time) you just let the clutch out with the tranny
engaged so the engine didn't run on. Of course you don't have that option.
:-}
Rick Girard
On Sun, May 30, 2010 at 6:54 AM, <Catz631@aol.com> wrote:
> Well, my old nemesis is back with a vengeance! Yesterday was a very hot
> (96degree) , muggy,lousy,typical Florida summer day. So why not go fly. I
> did and after shutting my engine down it slung itself backwards at least
> 5-10 engine revolutions (not blades) If I would have turned the mags back
> on, and the jugs didn't blow I betI I could have backed into my parking
> spot! Everyone that saw this was amazed. They have never seen an engine do
> this. It has done this too me before about 5 times but never turned
> backwards that many revolutions.
> Now I do realize that I am the ONLY person in the world that has had this
> problem (verified by calls to tech reps at Lockwood and LEAF) but I would
> like this to stop. It's beginning to give me the RA (red ass)
> I only mention this again on this forum to see if some of you gurus agree
> with me on the procedure I will follow from here. I plan on getting an oil
> sample today and sending it off for analysis for metal to see if there is
> any cam damage from collapsed lifters. As I understand it turning the engine
> backwards could ingest air into the lifters thus causing one or more to
> collapse thus causing scuffing of the cam lobes (ie:metal)
> I have performed the valve lifter check after each of these events and at
> no time in the past have the clearances been greater than 20 thousands which
> according to the bulletin would indicate air in the lifters. The oil filter
> has always been free of metal also.
> After this last event at an outlying field, I restarted the engine, the
> oil pressure fluctuated a little bit at idle (as it always does since I have
> had the airplane) normal rpm produced steady oil pressure so I flew the
> aircraft back home (10 minutes) Today I might do another check for air in
> the lifters but I am sure if any was there, it is gone due to the 10-15
> minutes of flight time home.
> I believe the major causes of this problem are, old premium fuel (over30
> days as I was on vacation) high outside temps and the fixed engine ignition
> timing is off somewhat. I had added octane booster to the fuel as this has
> helped in the past but probably not added enough.
> I have borescopped the engine cylinders and they seem relatively free of
> carbon (250 hrstt engine)
> Any ideas?
> I am running a Warp drive prop. I have even thought of going back to the
> Kiev prop. It is about a pound lighter than the Warp. It,s momentum would be
> less than the Warp. Maybe that would do it. Mystery!
> Thanks,
> Dick Maddux
> Kitfox 4
> Milton,Fl
>
> *
>
> *
>
>
Message 5
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: 912UL turning backwards on shutdown |
dropping idle speed sounds good but will add to gear box wear dramatically. Most
carburated auto added the solenoid in the 70s as they were higher compression
engines .
--------
Rotax Dealer, Ontario Canada
http://www.cfisher.com/
Awesome *New Forum *
http://rotaxaircraft.com/forum/
Realtime Kitfox movies to separate the internet chatter from the truth
http://www.youtube.com/profile_videos?user=kitfoxflyer
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=299354#299354
Message 6
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: 912UL turning backwards on shutdown |
Hi Dick,
Sorry to hear your having this problem. I think I would be getting a little on
the RA side too. If you know the carbs are balanced and the idle is set to 1700-1800
rpm then I would dump your fuel (all of it) and try some 100LL and see
if that makes a difference. It really could be old fuel and a badly reduced octane
number. My first guess if the idle and carb balance is good is a fuel issue.
After you try a normal shut down with 100LL, which I hope works, then try
shutting off one mag for 10-15 seconds then turn the last one off, but use the
100LL first to see if it makes any difference.
--------
Roger Lee
Tucson, Az.
Light Sport Repairman - Maintenance Rated
Rotax Repair Center
520-574-1080
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=299356#299356
Message 7
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: 912 oil purge proceedure |
Hi Ross,
Most of the time when people are having oil pressure issues it is the oil pressure
sending unit or a bad ground. It usually is not really an engine oil pressure
problem. That's why I advise most people to put a mechanical gauge in line
and double check the real pressure and it will usually tell you right away what
the problem is. Glad it worked out.
--------
Roger Lee
Tucson, Az.
Light Sport Repairman - Maintenance Rated
Rotax Repair Center
520-574-1080
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=299358#299358
Message 8
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | 912UL turning backwards on shutdown |
Dick:
Perhaps the thing to do is to shut off your fuel and starve the engine.
Similar to what they do with certified engines. It may take a few minutes
to refill the float bowl to restart though.
In the meantime it sure sounds to me like your engine is running a bit too
hot while taxiing and when you cut the ignition head temps cause
pre-ignition... enough to spin the engine backward. Perhaps a minute or so
at a fast idle before shutting down the engine will help.
Noel
From: owner-rotaxengines-list-server@matronics.com
[mailto:owner-rotaxengines-list-server@matronics.com] On Behalf Of
Catz631@aol.com
Sent: May 30, 2010 9:24 AM
Subject: RotaxEngines-List: 912UL turning backwards on shutdown
Well, my old nemesis is back with a vengeance! Yesterday was a very hot
(96degree) , muggy,lousy,typical Florida summer day. So why not go fly. I
did and after shutting my engine down it slung itself backwards at least
5-10 engine revolutions (not blades) If I would have turned the mags back
on, and the jugs didn't blow I betI I could have backed into my parking
spot! Everyone that saw this was amazed. They have never seen an engine do
this. It has done this too me before about 5 times but never turned
backwards that many revolutions.
Now I do realize that I am the ONLY person in the world that has had this
problem (verified by calls to tech reps at Lockwood and LEAF) but I would
like this to stop. It's beginning to give me the RA (red ass)
I only mention this again on this forum to see if some of you gurus agree
with me on the procedure I will follow from here. I plan on getting an oil
sample today and sending it off for analysis for metal to see if there is
any cam damage from collapsed lifters. As I understand it turning the engine
backwards could ingest air into the lifters thus causing one or more to
collapse thus causing scuffing of the cam lobes (ie:metal)
I have performed the valve lifter check after each of these events and at
no time in the past have the clearances been greater than 20 thousands which
according to the bulletin would indicate air in the lifters. The oil filter
has always been free of metal also.
After this last event at an outlying field, I restarted the engine, the oil
pressure fluctuated a little bit at idle (as it always does since I have had
the airplane) normal rpm produced steady oil pressure so I flew the aircraft
back home (10 minutes) Today I might do another check for air in the lifters
but I am sure if any was there, it is gone due to the 10-15 minutes of
flight time home.
I believe the major causes of this problem are, old premium fuel (over30
days as I was on vacation) high outside temps and the fixed engine ignition
timing is off somewhat. I had added octane booster to the fuel as this has
helped in the past but probably not added enough.
I have borescopped the engine cylinders and they seem relatively free of
carbon (250 hrstt engine)
Any ideas?
I am running a Warp drive prop. I have even thought of going back to the
Kiev prop. It is about a pound lighter than the Warp. It,s momentum would be
less than the Warp. Maybe that would do it. Mystery!
Thanks,
Dick Maddux
Kitfox 4
Milton,Fl
Message 9
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | 912UL turning backwards on shutdown |
I would not do this. A while back I had a P lead break and the only way to
shut down was to turn the fuel off. After five minutes one carb ran out of
gas before the other and it REALLY ran bad for another minute until the oth
er carb ran out of fuel. The motor shook so bad I was worried about it rema
ining attached to the mount. In fact, shortly after that is when I found a
large crack in my engine mount.
Scott
--- On Sun, 5/30/10, Noel Loveys <noelloveys@yahoo.ca> wrote:
From: Noel Loveys <noelloveys@yahoo.ca>
Subject: RE: RotaxEngines-List: 912UL turning backwards on shutdown
=0A=0A=0A =0A =0A=0A=0A=0A=0A=0A=0ADick: =0A=0A - =0A=0APerhaps the thing
to do is to=0Ashut off your fuel and starve the engine.- Similar to what
they do with=0Acertified engines.- It may take a few minutes to refill t
he float bowl to=0Arestart though. =0A=0A - =0A=0AIn the meantime it sure
=0Asounds to me like your engine is running a bit too hot while taxiing and
when=0Ayou cut the ignition head temps cause pre-ignition... enough to spi
n the engine=0Abackward.- Perhaps a minute or so at a fast idle before sh
utting down the=0Aengine will help. =0A=0A - =0A=0ANoel =0A=0A - =0A=0A
=0A=0A=0A=0AFrom:=0Aowner-rotaxengines-list-server@matronics.com=0A[mailto:
owner-rotaxengines-list-server@matronics.com] On Behalf Of Catz631@aol.com
=0ASent: May 30, 2010 9:24 AM
=0ATo: rotaxengines-list@matronics.com
=0ASubject: RotaxEngines-List: 912UL turning backwards on shutdown =0A=0A
=0A=0A=0A=0A - =0A=0A=0A=0AWell,=0Amy old nemesis is back with a vengeanc
e! Yesterday was a very hot=0A(96degree)-, muggy,lousy,typical Florida su
mmer day. So why not go fly. I=0Adid and after shutting my engine down it s
lung itself backwards at least 5-10=0Aengine revolutions (not blades) If I
would have turned the mags back on, and=0Athe jugs didn't blow I betI I-c
ould have backed into my parking spot!=0AEveryone that saw this was amazed.
They have never seen an engine do this. It=0Ahas done this too me before a
bout 5 times but never-turned backwards that=0Amany revolutions. =0A=0A
=0A=0A=0A=0A-Now=0AI do realize that I am the ONLY person in the world th
at has had this problem=0A(verified by calls to tech reps at Lockwood and L
EAF) but I would like this to=0Astop. It's beginning to give me the RA (red
ass) =0A=0A=0A=0A=0A=0A-I=0Aonly mention this again on this forum to see
if some of you gurus agree with me=0Aon the procedure I will follow from h
ere. I plan on getting an oil sample=0Atoday-and sending it off for analy
sis for metal-to see if there is=0Aany cam damage from collapsed lifters.
As-I understand it turning the=0Aengine backwards could ingest air into
the lifters thus causing one or more to=0Acollapse thus causing scuffing of
the cam lobes (ie:metal) =0A=0A=0A=0A=0A=0A-I=0Ahave performed the valv
e lifter check after each of these events and at no time=0Ain the past-ha
ve the clearances been greater than 20 thousands which=0Aaccording to the b
ulletin would indicate air in the lifters. The oil filter has=0Aalways been
free of metal also. =0A=0A=0A=0A=0A=0A-After=0Athis last event at an out
lying field, I restarted the engine, the oil pressure=0Afluctuated a little
bit at idle (as it always does since I have had the=0Aairplane) normal rpm
produced steady oil pressure so I flew the aircraft back=0Ahome (10 minute
s) Today I might do another check for air in the lifters but I=0Aam sure if
any was there, it is gone-due to the 10-15 minutes of flight=0Atime home
. =0A=0A=0A=0A=0A=0A-I=0Abelieve--the major causes of this problem ar
e, old premium fuel=0A(over30 days as I was on vacation) high outside temps
and the fixed engine=0Aignition timing is off somewhat. I had added octane
booster to the fuel as this=0Ahas helped in the past but probably not adde
d-enough. =0A=0A=0A=0A=0A=0A-I=0Ahave borescopped the engine cylinders
and they seem relatively free of carbon=0A(250 hrstt engine) =0A=0A=0A=0A
=0A=0A-=0AAny ideas? =0A=0A=0A=0A=0A=0A-I=0Aam running a Warp drive pro
p. I have even thought of going back to the Kiev=0Aprop. It is about a poun
d lighter than the Warp. It,s momentum would be less=0Athan the Warp. Maybe
that would do it. Mystery! =0A=0A=0A=0A=0A=0A---------
-------------------------
=0AThanks, =0A=0A=0A=0A=0A=0A---------------
-------------------------
-----=0ADick Maddux =0A=0A=0A=0A=0A=0A---------
-------------------------
-----------=0AKitfox 4 =0A=0A=0A=0A=0A=0A----
-------------------------
----------------=0AMilton,Fl =0A=0A=0A=0A
- -http://www.matronics.com/Navigator?RotaxEngines-Listhttp://forums.ma
tronics.comhttp://www.matronics.com/contribution - =0A=0A=0A=0A=0A=0A=0A
=0A
Message 10
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: 912UL turning backwards on shutdown |
Check again... I think Rotax actually ALLOWS the use of up to 10% eth.
That's a stretch from recommending its use.
Ethanol has a RON of 116 and will actually increase the RON of just about
any gas available today. That is if you have a source of fresh 99.99% eth
to add to your gas. Ethanol will also absorb moisture right out of the air
and because it is already in the fuel that's the wrong place for moisture to
be.
There are several other reasons why I don't like ethanol in fuel and I've
gone over those countless times.
What Dave says about, is premium actually premium, is a good question. I
don't know anyone who has the equipment to do accurate flash testing. I do
know that a few years ago the Newfoundland Constabulary was having problems
with a factory built hotrod they called a police car. Technicians were sent
from GM to find out what was causing the backfiring... after two weeks of
building and rebuilding the engine the test results from GM's own lab came
back that the fuel was a very low octane... low even for regular fuel. The
Constab. then tested all the premium gas sold in the area and found over 50
pumps only one actually had premium fuel in it. Letters went out to all the
oil companies and the result of that was one oil company returned a letter
saying they would no longer conduct flash tests for the Constabulary.
The answer to your problem may be as easy as changing where you buy your
gas. If you want to foot the $50 or so bill to have a flash test done on
your fuel you may find in fact your supplier is in fact cheating you. If
this happens be sure to inform the authorities about what is going on.
After all that is fraud.
Always buy the freshest gas you can get. Large busy stations have more turn
over in fuel so generally have fresher fuel in their tanks.
With ethanol, if you must use it, don't let it sit in your plane's tanks for
any longer than a day or two. In that time ethanol can evaporate and what
doesn't evaporate will absorb some moisture (water) right out of the air.
If you have to store ethanol fuel longer than that, store it in a sealed
container not in the plane's tanks.
Noel
-----Original Message-----
From: owner-rotaxengines-list-server@matronics.com
[mailto:owner-rotaxengines-list-server@matronics.com] On Behalf Of dave
Sent: May 30, 2010 10:08 AM
Subject: RotaxEngines-List: Re: 912UL turning backwards on shutdown
Dick,
Are you using avgas or auto premium ?
Sounds like pre ignition-- since you likley do not have a mixtue cut off try
shutting off the fuel vakve at shut down.
912 UL will run fine on auto regular 87 grade --with or without ethanol.
Acutally you might want to run a tank of ethanol regular gas through it and
see if that helps.
Although many armchair captains will say bal bla bla about ethanol Rtoax
does infact recoment the use of it up to 10%.
Also who says that premium is always premium gas at the pumps. I VERY
rarely use premium if ever on Rotax 2 stroke and 912 UL . 912 S yes preium
auto fuel only. NO avgas.
Just in from 1.5 flight on ethanol gas -- I am over 1000 hours onethanl gas
no personally without a gitch so far. :)
--------
Rotax Dealer, Ontario Canada
http://www.cfisher.com/
Awesome *New Forum *
http://rotaxaircraft.com/forum/
Realtime Kitfox movies to separate the internet chatter from the truth
http://www.youtube.com/profile_videos?user=kitfoxflyer
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=299344#299344
Message 11
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: 912UL turning backwards on shutdown |
I agree with Dave on this one... AVGAS should only be used as a last
alternative and if you really have to use AVGAS then get some lead scavenger
to put in it.
The idea of having a look with a borescope has lots of merit!
Noel
-----Original Message-----
From: owner-rotaxengines-list-server@matronics.com
[mailto:owner-rotaxengines-list-server@matronics.com] On Behalf Of Roger Lee
Sent: May 30, 2010 11:06 AM
Subject: RotaxEngines-List: Re: 912UL turning backwards on shutdown
Hi Dick,
Sorry to hear your having this problem. I think I would be getting a little
on the RA side too. If you know the carbs are balanced and the idle is set
to 1700-1800 rpm then I would dump your fuel (all of it) and try some 100LL
and see if that makes a difference. It really could be old fuel and a badly
reduced octane number. My first guess if the idle and carb balance is good
is a fuel issue. After you try a normal shut down with 100LL, which I hope
works, then try shutting off one mag for 10-15 seconds then turn the last
one off, but use the 100LL first to see if it makes any difference.
--------
Roger Lee
Tucson, Az.
Light Sport Repairman - Maintenance Rated
Rotax Repair Center
520-574-1080
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=299356#299356
Message 12
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | 912UL turning backwards on shutdown |
I never thought about one side running longer than the other side. That
pretty well puts paid to the idea of starving the engine. Pulling the
enricheners just before shutdown would probably flood the engine but may
stop the dieseling by cooling down the combustion chamber.
I suspect in warm weather you may have to go to a higher octane fuel to
prevent the detonation.
The idea of resetting the throttle so you will have a shutdown position
sounds ok if and only if you never use that position to idle the engine. I
had my idle on my 582 set to around 600 rpm. But I never idled the engine
at that speed. The only time I actually pulled the throttle all the way out
was when landing. As soon as I was on the water I would increase the
throttle to around 1500 or even 2000 wherever the engine ran smoothest.
I still think the first thing I would do is buy my gas at a different
station..... and probably try high octane gas that flashes at a higher
temperature.
Noel
From: owner-rotaxengines-list-server@matronics.com
[mailto:owner-rotaxengines-list-server@matronics.com] On Behalf Of Scott
DeMeyer
Sent: May 30, 2010 11:42 AM
Subject: RE: RotaxEngines-List: 912UL turning backwards on shutdown
I would not do this. A while back I had a P lead break and the only way to
shut down was to turn the fuel off. After five minutes one carb ran out of
gas before the other and it REALLY ran bad for another minute until the
other carb ran out of fuel. The motor shook so bad I was worried about it
remaining attached to the mount. In fact, shortly after that is when I found
a large crack in my engine mount.
Scott
--- On Sun, 5/30/10, Noel Loveys <noelloveys@yahoo.ca> wrote:
From: Noel Loveys <noelloveys@yahoo.ca>
Subject: RE: RotaxEngines-List: 912UL turning backwards on shutdown
Dick:
Perhaps the thing to do is to shut off your fuel and starve the engine.
Similar to what they do with certified engines. It may take a few minutes
to refill the float bowl to restart though.
In the meantime it sure sounds to me like your engine is running a bit too
hot while taxiing and when you cut the ignition head temps cause
pre-ignition... enough to spin the engine backward. Perhaps a minute or so
at a fast idle before shutting down the engine will help.
Noel
From: owner-rotaxengines-list-server@matronics.com
[mailto:owner-rotaxengines-list-server@matronics.com] On Behalf Of
Catz631@aol.com
Sent: May 30, 2010 9:24 AM
Subject: RotaxEngines-List: 912UL turning backwards on shutdown
Well, my old nemesis is back with a vengeance! Yesterday was a very hot
(96degree) , muggy,lousy,typical Florida summer day. So why not go fly. I
did and after shutting my engine down it slung itself backwards at least
5-10 engine revolutions (not blades) If I would have turned the mags back
on, and the jugs didn't blow I betI I could have backed into my parking
spot! Everyone that saw this was amazed. They have never seen an engine do
this. It has done this too me before about 5 times but never turned
backwards that many revolutions.
Now I do realize that I am the ONLY person in the world that has had this
problem (verified by calls to tech reps at Lockwood and LEAF) but I would
like this to stop. It's beginning to give me the RA (red ass)
I only mention this again on this forum to see if some of you gurus agree
with me on the procedure I will follow from here. I plan on getting an oil
sample today and sending it off for analysis for metal to see if there is
any cam damage from collapsed lifters. As I understand it turning the engine
backwards could ingest air into the lifters thus causing one or more to
collapse thus causing scuffing of the cam lobes (ie:metal)
I have performed the valve lifter check after each of these events and at
no time in the past have the clearances been greater than 20 thousands which
according to the bulletin would indicate air in the lifters. The oil filter
has always been free of metal also.
After this last event at an outlying field, I restarted the engine, the oil
pressure fluctuated a little bit at idle (as it always does since I have had
the airplane) normal rpm produced steady oil pressure so I flew the aircraft
back home (10 minutes) Today I might do another check for air in the lifters
but I am sure if any was there, it is gone due to the 10-15 minutes of
flight time home.
I believe the major causes of this problem are, old premium fuel (over30
days as I was on vacation) high outside temps and the fixed engine ignition
timing is off somewhat. I had added octane booster to the fuel as this has
helped in the past but probably not added enough.
I have borescopped the engine cylinders and they seem relatively free of
carbon (250 hrstt engine)
Any ideas?
I am running a Warp drive prop. I have even thought of going back to the
Kiev prop. It is about a pound lighter than the Warp. It,s momentum would be
less than the Warp. Maybe that would do it. Mystery!
Thanks,
Dick Maddux
Kitfox 4
Milton,Fl
http://www.matronics.com/Navigator?RotaxEngines-List
http://forums.matronics.com
http://www.matronics.com/contribution
http://www.matronics.com/Navigator?RotaxEngines-List
http://www.matronics.com/Navigator?RotaxEngines-List
http://www.matronics.com/contribution
Message 13
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: 912UL turning backwards on shutdown |
Hi Dick
I had a 1972 Yamaha RT-2 360 single cylinder 2 stroke. Often after a highway ride
in hot temps upon shut down it would give a pop and turn backwards. Easy on
a bike to deal with, i would just put in gear and stall by letting out clutch.
Once after a highway ride on a hot day decided to take a compression test, boy
the compression gage didn't like the cylinder firing with full throttle at
all! What must have happened is there was a glowing piece of carbon that fired
the fuel air mixture.
Anyway with your problem:
**Give a try engaging the enriching circuit for a little bit before shut down to
help cool things off, try both ways, shutting down with enrichment rich, and
also after attempt to cool things a bit with enrichment lean
**I have heard that high temps of ignition boxes causes inability to shut down
engine. Circuit fails with heat but when cooled down begins to work again. With
such a wishy washy thing I would imagine you could get it to intermittent fire
which is perhaps your problem? Anyway to add a bit of extra cooling to ignition
modules?
**OK here we go, I think cooling the cylinder heads, pistons and ignition modules
before shut down is in order to test. Before shut down point into wind, richen
with choke and try 2750 or 3000 rpms for 15 or 20 seconds, idle with choke
for 5 or 10 seconds and shut down. Try same but at idle turn off choke.
Other stuff:
**Too lean is no good upon shutting down if a glowing piece of carbon is your culprit,
did you adjust idle mixture? If not give it a go on a hot day, perhaps
go just a tad bit richer.
**If glowing carbon is problem, give the plane a decarbonization. Best way of course
is to pull jugs, but on my 914 I will use water. If you ever had a look
at a automobile engine that has a water leak, ain't very hard to find the leak,
the cylinder and head is scrubbed clean! I have owned a number of Volvo turbo
station wagons, the 1983 with aircooled Garette turbo very similar to 914 turbo.
After a gazillion miles they would tend to ping even with high test fuel.
No problem, pick a hot summer day, go up a 1 mile not too far from my home hill
with full throttle, quick pull over on side street and pour a quart of distilled
water through a nipple on manifold. I add water fast enough to begin to
kill motor, but increase throttle. I do this till I am about 1/4 throttle and
use water injection to keep RPMs ~3,000. I will do this 3 times, first with water,
second time with a can of Seafoam (get at most auto parts stores) and third
time with water. I only use distilled water. Been doing that since 1983. With
Rotax my idea was to try injection in manifold pressure input between cylinders
on cross tube. Run a tube back to a safe distance, could probably use a super
soaker for water, oil can for Seafoam.
**Another thought, Rotax is adamant you use Whacker thermal conductive compound
on spark plug threads. I spoke with research guy who tested various compounds
and said Whacker is hands down winner. Best use that (I am). I remember filling
my brothers Jawa motorcycle carb with model aeroplane fuel, it started and
began to scream (way too lean because such a high alcohol content) and when he
hit kill switch, nothing, it kept on running till he put in gear and stalled.
**Is spark plugs very full of carbon to have a glowing ember and act like a glow
plug?
**Are spark plugs proper heat range? This is critical.
**True that the slower the idle is below 1800RPM the more loading of gearbox. I
think I read there is 10 times more loading at idle compared to 5,000 rpm. Having
carbs balanced (and mixture adjusted) helps. With a Europa if you have idle
set at 1800RPM on ground, you will have a hard time landing any sort of short.
Best have idle on ground (stopped) able to get to 1450 (or 1400 even), this
way you can land shorter, remember when flying air flowing over prop will increase
RPM. Anyway just use throttle to keep 1800 or over on ground, but in your
case lowering for shut down will be a good thing.
Another thought is when you are doing 2750 or 3000 rpm choke cooling, give a mag
check. See if one is either not shutting down or giving a misfire. At this RPM
I doubt glowing carbon would cause this. A miss may be overheated or failing
ignition module.
If you suspect ignition modules, perhaps if easy have someone spray with water
mist to cool before shut down and see if that helps.
Wait a second, perhaps I remember you have a primer? If you do use that to help
cool motor before shut down.
Good luck
Ron Parigoris
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=299382#299382
Message 14
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: 912UL turning backwards on shutdown |
Hi Dick,
Are the carbs balanced?
The temporary use of 100LL is to determine if it is a poor fuel or Octane issue.
Running a few gallons of 100LL will tell you that fairly quickly. If your problem
goes away then you know it is nothing else. The 100LL is the easiest and
cheapest up front test. Drain the fuel and put in 5 gal. of 100LL and go fly
again. If it still happens then don't chase the fuel issue again and look at other
things. You need to rule out one issue at a time to make sure you find the
problem. This may also be a gearbox issue in part. Does your 912 have an overload
clutch and how many hours? I need to do a little more checking, but do
the other test first.
--------
Roger Lee
Tucson, Az.
Light Sport Repairman - Maintenance Rated
Rotax Repair Center
520-574-1080
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=299386#299386
Other Matronics Email List Services
These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.
-- Please support this service by making your Contribution today! --
|