Today's Message Index:
----------------------
1. 02:31 AM - Re: Fuel pump failure (Mike Hoffman)
2. 05:32 AM - Re: Re: Fuel pump failure ()
3. 05:47 AM - Fuel pump failure (Joe Spencer)
4. 06:24 AM - Re: Fuel pump failure (Roger Lee)
5. 07:43 AM - Fuel pump failure (Joe Spencer)
6. 08:34 AM - Re: Fuel pump failure (Roger Lee)
7. 09:10 AM - Fuel pump failure (Joe Spencer)
8. 09:56 AM - Re: Fuel pump failure (Guy Buchanan)
9. 10:39 AM - Annual (Jim Hazen)
10. 10:52 AM - Re: Annual (Richard Girard)
11. 11:03 AM - Re: Annual (Jim Hazen)
12. 11:04 AM - Re: Fuel pump failure (Roger Lee)
13. 11:24 AM - Re: Annual (Bob Comperini)
14. 12:25 PM - Re: Annual (Roger Lee)
15. 12:41 PM - Re: Re: Fuel pump failure ()
16. 12:45 PM - Fuel pump failure (Joe Spencer)
17. 01:33 PM - Re: Annual (Richard Girard)
18. 02:04 PM - Re: Fuel pump failure (Roger Lee)
19. 04:47 PM - Fuel pump failure (Joe Spencer)
20. 04:54 PM - Re: Fuel pump failure (=?ISO-8859-1?Q?J=F3hann_J=F3hannsson?=)
21. 05:38 PM - Re: Fuel pump failure (Craig Payne)
22. 05:53 PM - Fuel pump failure (Joe Spencer)
23. 06:09 PM - Re: Fuel pump failure (Ken Ryan)
24. 06:38 PM - Re: Fuel pump failure (Roger Lee)
Message 1
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| Subject: | Re: Fuel pump failure |
Yes, my pump failed at 8 hours. It was leaking fuel from the pump body vent hole.
I found fuel stain on the front of my cowl and engine. I was told by lockwood
aviation that is a problem with the pumps and that 1 out of 4 are bad. I have
been waiting for my new pump since before Christmas and was told it could be
1 or 2 more weeks.
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=281402#281402
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| Subject: | Re: Fuel pump failure |
Hi mike
You can obtain a better quality pump from
http://www.billetpump.com
TBO of more than 2800 hours
ivor
---- Mike Hoffman <mhoffman9@tampabay.rr.com> wrote:
>
> Yes, my pump failed at 8 hours. It was leaking fuel from the pump body vent hole.
I found fuel stain on the front of my cowl and engine. I was told by lockwood
aviation that is a problem with the pumps and that 1 out of 4 are bad. I
have been waiting for my new pump since before Christmas and was told it could
be 1 or 2 more weeks.
>
>
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=281402#281402
>
>
>
>
>
>
>
>
>
>
Message 3
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| Subject: | Fuel pump failure |
>Hi Joe,
>The normal fuel pressure is anywhere from 2.2 (low) -5.8 (max) psi.
Most run from
3.2-4.6 psi. If yours has been higher that's ok, but a fuel pressure
between
3.1 - 4.6 is very normal. Mine is only 3.4 - 3.6 psi. The other thing
is where
is your fuel pressure sensor mounted? Do you have a fuel pressure
dampener
in line between the sender and the panel? If your fuel pressure sender
is mounted
on top of the fuel cross over line between the carbs then vibration is
your
enemy and many people are remote mounting them which is Rotax approved.
One
last thing are you a high wing or low wing and are you running an
electric auxiliary
pump?
--------
Roger Lee
Thanks for the replies and info...it's not so much the psi the pump is
putting out as the fact that the psi is fluctuating (between 4.2 and 5.0
psi). My gauge is a direct read gauge with the pressure pickoff just
upstream of the left carb. The plane is a Zenith 701. Yes I do have a
backup electric pump that puts out 3 psi; and also have gravity feed as
long as the pitch attitude isn't too high. The fluctuating pressure
reading is unaffected by the electric pump being either on or off, as
expected, as long as the pressure is above the 3 psi the electric pump
puts out. The thing quit on me last week in level flight straight and
level...fuel pressure was zero at the time of the stoppage with both
pumps on, indicating either out of gas, stopped up vents or a blockage
or leak somewhere. After getting it on the ground, the vents were open
and I stuck the tanks and both of them had enough fuel to feed in level
flight. I pulled the hood and leak checked it with the electric pump, no
leaks.Pulled the fuel filter and cleaned it, it was a little grungy and
is suspect...ran it up a while on the ground and all was normal with
steady pressure, was able to get it the 3 miles to the strip altho the
fuel pressure started fluctuating enroute. Have troubleshot everything
and haven't found anything but the fuel filter so far...but am wondering
if there have been instances of a failing engine driven pump possibly
causing some sort of blockage in the pump while failing and also
wondering if fluctuating pressure is a known early warning of impending
failure with this pump. It should have gravity fed unless the fuel
filter was indeed blocked or the pump was somehow blocked
Thanks again
Joe
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| Subject: | Re: Fuel pump failure |
Hi Joe,
Even if the mechanical pump failed the electric pump should have been more than
adequate. The mechanical pumps fail open. So if the mechanical pump quit and
you still ran dry then I think you have a blockage somewhere or for some reason
a vent issue. A blockage can move back and forth within a line depending on
fuel demand. At high flow times it flows to a choke point, when little fuel is
on demand or the engine is shut off it can move or float away from the choke
point until you demand a lot of flow again. I would double check my vents and
flow fuel through all my fuel lines into a can or something to flush them. I would
also check my carb float bowls as they can have tattletale signs of crud.
This doesn't sound like a pump problem.
--------
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=281422#281422
Message 5
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| Subject: | Fuel pump failure |
>Even if the mechanical pump failed the electric pump should have been
more than
adequate.
Thanks. Agreed. Also, it should have gravity fed.
>The mechanical pumps fail open
This is what I was looking for. Thanks for that info. I have gravity
feed checked everything up to the mechanical pump and am just waiting
for the hangar to warm up and will do that this morning.
The pressure fluctuation is attitude related...when lowering the nose
the pressure increases from about 4.2 to about 4.7 or 4.8. Makes me
think there is something floating around in there that is blocking feed
but have checked everything from the mechanical pump back and it's all
clean. The vents are definitely open, there's no water in anything.
As an aside, I am wondering about not running a mechanical pump now,
what with gravity feed available. I could install 2 electric pumps for
redundancy for steep takeoffs/climb outs where it wouldn't gravity feed
and block off the mechanical pump pad.I should be able to get home on
gravity feed if it total electric fails...do you know of any problems
with blocking it off and not running the pump?
Thanks again
Joe
Message 6
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| Subject: | Re: Fuel pump failure |
There are people that do not have the mechanical pump and have a solid gasket/plate
over the opening and only run electric pumps. I saw a 914 like this the other
day on a Zenith 701. Way over powered.
--------
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=281471#281471
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| Subject: | Fuel pump failure |
Well after fooling with this thing all morning I learned a few things
that I thought I would pass along...
It's a Zenith 701 high wing with a 912s. It should gravity feed and does
but after going thru the fuel valve, fuel filter, electric pump and
mechanical pump there is so little flow at the carb that I now don't
consider it to be gravity feed capable. The stream out of the line just
before the carb is tiny, less than the diameter of a pencil lead...and
weak. Some of you older guys might know what I'm talking about here.
The filter is one of the i think it's a purolator ones with the glass
bowl and cast chrome body and a plastic screen inside. They've been
around forever and I always liked them for certain apps. But the cast
body means rather thick walled nipples and a small flow hole, further
restricting the flow. I subbed in a length of 1/4 OD .035 wall tube for
the filter and the flow is still too weak for comfort for this old
guy...
FWIW
Joe
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| Subject: | Re: Fuel pump failure |
At 09:05 AM 1/14/2010, you wrote:
>The filter is one of the i think it's a purolator ones with the
>glass bowl and cast chrome body and a plastic screen inside.
I've had problems with these "gumming up". Try a new filter element
and see if the flow is any different. Don't know why they blocked but
I had it happen the three of them.
Guy Buchanan
San Diego, CA
K-IV 1200 / 582-C / Warp / 400 hrs. and counting
Message 9
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Can an LSA Repairman do annual inspections on an SLSA?
Jim Hazen
Message 10
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If you took the 16 hour course (LSARI), no. If you took the 120 hour course
(LSARM), yes.
Rick Girard
On Thu, Jan 14, 2010 at 12:38 PM, Jim Hazen <jlhazen@copper.net> wrote:
>
> Can an LSA Repairman do annual inspections on an SLSA?
> Jim Hazen
>
>
Message 11
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Can someone else with a LSARM certificate do an annual on my plane.
-----Original Message-----
From: Richard Girard <aslsa.rng@gmail.com>
Sent: Thursday, January 14, 2010 11:51
Subject: Re: RotaxEngines-List: Annual
If you took the 16 hour course (LSARI), no. If you took the 120 hour course
(LSARM), yes.
Rick Girard
On Thu, Jan 14, 2010 at 12:38 PM, Jim Hazen <jlhazen@copper.net> wrote:
>
> Can an LSA Repairman do annual inspections on an SLSA?
> Jim Hazen
>
>
[The entire original message is not included]
Message 12
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| Subject: | Re: Fuel pump failure |
Hi Joe,
I'm with Guy. First thing is toss the old filter element. Then go back at the start
of the flow at the fuel tank and start finding out why it is such a weak
flow. If I open my gasolator my fuel just pours out and a solid stream which is
before the pump. Then pop off the float bowls and see what kind of flow there
is at that point. Start at point "A" and work you way through the system until
you can say this is my choke point or obstruction. I bet along the way you'll
find something. Is this something that just started out of the blue?
--------
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=281507#281507
Message 13
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On 11:03 AM 1/14/2010, Jim Hazen wrote:
>
>Can someone else with a LSARM certificate do an annual on my plane.
Yes, if your plane is certificated as an E-LSA, or S-LSA (and the repairman has
the appropriate category/class.. airplane vs weightshift, etc)
--
Bob Comperini
e-mail: bob@fly-ul.com
WWW: http://www.fly-ul.com
Message 14
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Hi Guys,
If you have an ELSA only you, the owner, with the 16 hr course can do your own
annual condition inspection. If you or someone else has the 120 hr RLSM-A then
you can do yours or anyone else's whether it is ELSA or SLSA. You have to own
the plane if you take the 16 hr. course for an ELSA. Someone else with the 16
hr. course can not do your inspection. When you finish the 16 hr. course you
have to send paperwork into the FAA and get listed for that plane you own. You
can only be listed for these approvals if you own the plane. You could own 4
ELSA planes and so long as you have the 16 hr. course and have them listed with
the FAA then you could inspect all 4. If you do not have either course then
you can not do your inspection on an ELSA or SLSA and need either an RLSM-A or
an A&P. For an SLSA an A&P must have a Rotax class to be legal to work on a Rotax
engine if the plane Mfg. says follow the Rotax manual for the inspection
which most do.
So everyone is on the same page a Light Sport Repairman with a maint. rating should
sign it in the log as: RLSM-A (airplane) or RLSM-WS (weight shift) or RLSM-PP
(powered parachute) which ever is applicable for your credentials.
On an ELSA plane as with a regular experimental anyone can do work other than an
inspection.
--------
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=281517#281517
Message 15
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| Subject: | Re: Fuel pump failure |
Hi Roger
I have a 914 with electric pumps, but if you remove the blanking plate you will
find a fuel pump Cam to drive a mechanical pump,
ivor
---- Roger Lee <ssadiver1@yahoo.com> wrote:
>
> There are people that do not have the mechanical pump and have a solid gasket/plate
over the opening and only run electric pumps. I saw a 914 like this the
other day on a Zenith 701. Way over powered.
>
> --------
> 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=281471#281471
>
>
>
>
>
>
>
>
>
>
Message 16
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| Subject: | Fuel pump failure |
Thanks guys
I have been thru the fuel plumbing twice now and in some areas 3 times.
I had hoped to find something definite. The loss of flow begins in the
climb from the cockpit floor to the mechanical fuel pump(that is a long
uninterrupted run of 1/4 ID tubing that I have taken apart and blown
thru 3 times, each time giving it a final check by blowing thru it with
my mouth...it is clear, no kinks, no obstructions) and gets increasingly
weak from the floor forward. There is no definite choke point but looks
to be a gradual and natural loss of flow from I guess distance from the
tank, friction of the flow thru the lines and the climb of the lines and
resulting loss of head pressure. By the time it gets to the carbs it is
really weak, as reported earlier. I realize this sounds theoretically
incorrect, and I would be skeptical if I wasn't the one that has seen it
and is reporting it. There is full flow at every point prior to that run
of tubing where the line starts its climb. As a final check I hooked up
a fresh clear line at the point where the loss of flow begins and held
it outside the plane at varying heights beginning at floor level and
gradually raised it to mechanical pump level...there was a definite loss
of flow as the test tube was raised, corresponding to what I saw with
the installed line.
Come to think of it, all of the gravity flow planes I have ever flown
had a bottom mounted carb with no climbs in the lines. I've got plenty
of flow at the bottom
Joe
Message 17
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Yes, with an LSARM (Light Sport Aircraft Repairman Maintenance) rating the
certificate holder can work on any E-LSA or S-LSA aircraft for which he/she
is rated. As an example I am rated for airplanes, weight shift control
aircraft, and powered parachutes. I can work on any of them (for the SLSA's
it also depends on who the manufacturers maintenance manual says can work on
their aircraft), but I couldn't work on a gyrocopter or sailplane even if
the manufacturer allows an LSARM.
Rick Girard
On Thu, Jan 14, 2010 at 1:03 PM, Jim Hazen <jlhazen@copper.net> wrote:
>
> Can someone else with a LSARM certificate do an annual on my plane.
>
>
> -----Original Message-----
> From: Richard Girard <aslsa.rng@gmail.com>
> Sent: Thursday, January 14, 2010 11:51
> To: rotaxengines-list@matronics.com
> Subject: Re: RotaxEngines-List: Annual
>
> If you took the 16 hour course (LSARI), no. If you took the 120 hour course
> (LSARM), yes.
>
> Rick Girard
>
> On Thu, Jan 14, 2010 at 12:38 PM, Jim Hazen <jlhazen@copper.net> wrote:
>
> >
> > Can an LSA Repairman do annual inspections on an SLSA?
> > Jim Hazen
> >
> >
> >
> >
> >
> >
> >
>
>
> [The entire original message is not included]
>
>
Message 18
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| Subject: | Re: Fuel pump failure |
Hi Joe,
Read my last comment, maybe it should be up front.
You may want to re-plumb up to the mechanical pump. I use 8 mm (5/16) line up to
the pump then it is reduced down. I would use at least 5/16 from every where
up to the pump. 1/4 with a long run can be too small. If you look at a Rotax
fuel pump the line in port is bigger than the line out port. This is a fairly
standard fuel line setup. I know some use 1/4" all the way through, but it isn't
supposed to be that way if you read Rotax writings. Larger up to the pump then
reduce it down to the carbs.
You may want to buy a cheap pressure gauge from 0-10 psi and put this in line before
the carbs and check the pressure. That will give you some more info.
My other questions are how many hours on the engine and how many hours on the carbs
since a rebuild or tear down inspection? You didn't say if this is a new
issue after many hours of run time or has been an issue up front?
One last thought or maybe it should be one of the first thoughts. Do you have a
recirculation line back to your gascolator or tanks. If you happen to get a vapor
lock in the right place the pressure will drop to zero. These pumps can't
pump air. The start of vapor lock will mimic these symptoms.
--------
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=281538#281538
Message 19
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| Subject: | Fuel pump failure |
Hi Joe,
>Read my last comment, maybe it should be up front.
>You may want to re-plumb up to the mechanical pump. I use 8 mm (5/16)
line up to
the pump then it is reduced down. I would use at least 5/16 from every
where
up to the pump. 1/4 with a long run can be too small. If you look at a
Rotax
fuel pump the line in port is bigger than the line out port. This is a
fairly
standard fuel line setup. I know some use 1/4" all the way through, but
it isn't
supposed to be that way if you read Rotax writings. Larger up to the
pump then
reduce it down to the carbs.
Understand. I saw the bigger inlet port today when I was checking
things. I am also thinking of a way to route the lines so they don't
have to climb from the floor to the pump
>You may want to buy a cheap pressure gauge from 0-10 psi and put this
in line before
the carbs and check the pressure. That will give you some more info.
Right. I have that now...it's plumbed in just upstream of the left carb.
A direct reading gauge. That's how I got all the pressure
readings/fluctuations
>My other questions are how many hours on the engine and how many hours
on the carbs
since a rebuild or tear down inspection? You didn't say if this is a new
issue after many hours of run time or has been an issue up front?
The engine/carbs have 160 hours since new. No problems at all til the
failure last week. Carbs have never been into.
>One last thought or maybe it should be one of the first thoughts. Do
you have a
recirculation line back to your gascolator or tanks. If you happen to
get a vapor
lock in the right place the pressure will drop to zero. These pumps
can't
pump air. The start of vapor lock will mimic these symptoms.
No return line. On the day of the failure it was about 35 degrees and
running avgas. Had been airborne for about an hour.
I flew it about an hour today after checking everything. No pressure
fluctuations or problems of any kind. Ran fine. I do believe it was the
fuel filter now. That is the only thing I found that might have been it.
The big thing I think I learned from this is that I don't consider it to
be able to gravity feed as it is now. I would encourage others running
high wing planes that you think will gravity feed in event of pump
failure to check the flow at the carb inlets if you haven't already
done so. After checking that I would have grounded mine if I didn't have
an electric backup pump.
Roger and others...thanks for all the info and I will definitely keep it
all in mind as I try to improve the fuel system...I would like to plumb
it w/o a low spot in the line routing but that may be difficult w/o
interfering with the 701 door opening. Thinking.
Thx again
Joe
Message 20
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| Subject: | Re: Fuel pump failure |
Hello Joe.
I also have the Zenith 701 and had the vented fuel caps provided with
the kit from Zenith. The fuel was limited when the aircraft was
airborne due to low pressure created on top of the wing. I had to weld
a tube facing forward into the caps to help with the flow, to increase
the pressure inside the wing tanks.
It has not effected the engine run, because i have the header tank D
type installed and the mechanical pumps is sufficient for feeding the
engine, but I have an electrical pump to transfer the fuel from the
wing tanks to the header tank. Just need to get the flow started with
the electrical pump and can turn it off as soon the flow starts. But
most often leave it on to speed up the fuel transfer.
Just an idea.
Best of luck finding the problem.
Johann G.
Iceland.
On 14.1.2010, at 20:44, Joe Spencer wrote:
> Thanks guys
> I have been thru the fuel plumbing twice now and in some areas 3
> times. I had hoped to find something definite. The loss of flow
> begins in the climb from the cockpit floor to the mechanical fuel
> pump(that is a long uninterrupted run of 1/4 ID tubing that I have
> taken apart and blown thru 3 times, each time giving it a final
> check by blowing thru it with my mouth...it is clear, no kinks, no
> obstructions) and gets increasingly weak from the floor forward.
> There is no definite choke point but looks to be a gradual and
> natural loss of flow from I guess distance from the tank, friction
> of the flow thru the lines and the climb of the lines and resulting
> loss of head pressure. By the time it gets to the carbs it is really
> weak, as reported earlier. I realize this sounds theoretically
> incorrect, and I would be skeptical if I wasn't the one that has
> seen it and is reporting it. There is full flow at every point prior
> to that run of tubing where the line starts its climb. As a final
> check I hooked up a fresh clear line at the point where the loss of
> flow begins and held it outside the plane at varying heights
> beginning at floor level and gradually raised it to mechanical pump
> level...there was a definite loss of flow as the test tube was
> raised, corresponding to what I saw with the installed line.
> Come to think of it, all of the gravity flow planes I have ever
> flown had a bottom mounted carb with no climbs in the lines. I've
> got plenty of flow at the bottom
>
> Joe
>
>
Message 21
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| Subject: | Fuel pump failure |
> I would like to plumb it w/o a low spot in the line routing but that may
be difficult w/o interfering with the 701 door opening
Some 701 builders have run the lines forward at the wing root and down along
the steel tubes to the firewall.
-- Craig
_____
From: owner-rotaxengines-list-server@matronics.com
[mailto:owner-rotaxengines-list-server@matronics.com] On Behalf Of Joe
Spencer
Sent: Thursday, January 14, 2010 4:41 PM
Subject: RotaxEngines-List: Fuel pump failure
Hi Joe,
>Read my last comment, maybe it should be up front.
>You may want to re-plumb up to the mechanical pump. I use 8 mm (5/16) line
up to
the pump then it is reduced down. I would use at least 5/16 from every where
up to the pump. 1/4 with a long run can be too small. If you look at a Rotax
fuel pump the line in port is bigger than the line out port. This is a
fairly
standard fuel line setup. I know some use 1/4" all the way through, but it
isn't
supposed to be that way if you read Rotax writings. Larger up to the pump
then
reduce it down to the carbs.
Understand. I saw the bigger inlet port today when I was checking things. I
am also thinking of a way to route the lines so they don't have to climb
from the floor to the pump
>You may want to buy a cheap pressure gauge from 0-10 psi and put this in
line before
the carbs and check the pressure. That will give you some more info.
Right. I have that now...it's plumbed in just upstream of the left carb. A
direct reading gauge. That's how I got all the pressure
readings/fluctuations
>My other questions are how many hours on the engine and how many hours on
the carbs
since a rebuild or tear down inspection? You didn't say if this is a new
issue after many hours of run time or has been an issue up front?
The engine/carbs have 160 hours since new. No problems at all til the
failure last week. Carbs have never been into.
>One last thought or maybe it should be one of the first thoughts. Do you
have a
recirculation line back to your gascolator or tanks. If you happen to get a
vapor
lock in the right place the pressure will drop to zero. These pumps can't
pump air. The start of vapor lock will mimic these symptoms.
No return line. On the day of the failure it was about 35 degrees and
running avgas. Had been airborne for about an hour.
I flew it about an hour today after checking everything. No pressure
fluctuations or problems of any kind. Ran fine. I do believe it was the fuel
filter now. That is the only thing I found that might have been it. The big
thing I think I learned from this is that I don't consider it to be able to
gravity feed as it is now. I would encourage others running high wing planes
that you think will gravity feed in event of pump failure to check the flow
at the carb inlets if you haven't already done so. After checking that I
would have grounded mine if I didn't have an electric backup pump.
Roger and others...thanks for all the info and I will definitely keep it all
in mind as I try to improve the fuel system...I would like to plumb it w/o a
low spot in the line routing but that may be difficult w/o interfering with
the 701 door opening. Thinking.
Thx again
Joe
Message 22
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| Subject: | Fuel pump failure |
Johann
Thanks for that...I have the tubes welded on mine too, but no header
tank
Joe
Message 23
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| Subject: | Re: Fuel pump failure |
Joe said:
..I would like to plumb it w/o a low spot in the line routing but that may
be difficult w/o interfering with the 701 door opening.
I ask:
Don't you WANT a low spot as a water trap???
*
*
On Thu, Jan 14, 2010 at 3:40 PM, Joe Spencer <jpspencer@cableone.net> wrote:
> Hi Joe,
>
> >Read my last comment, maybe it should be up front.
>
> >You may want to re-plumb up to the mechanical pump. I use 8 mm (5/16) line
> up to
> the pump then it is reduced down. I would use at least 5/16 from every
> where
> up to the pump. 1/4 with a long run can be too small. If you look at a
> Rotax
> fuel pump the line in port is bigger than the line out port. This is a
> fairly
> standard fuel line setup. I know some use 1/4" all the way through, but it
> isn't
> supposed to be that way if you read Rotax writings. Larger up to the pump
> then
> reduce it down to the carbs.
>
> Understand. I saw the bigger inlet port today when I was checking things. I
> am also thinking of a way to route the lines so they don't have to climb
> from the floor to the pump
>
> **
>
> >You may want to buy a cheap pressure gauge from 0-10 psi and put this in
> line before
> the carbs and check the pressure. That will give you some more info.
>
> *Right. I have that now...it's plumbed in just upstream of the left carb.
> A direct reading gauge. That's how I got all the pressure
> readings/fluctuations*
>
> >My other questions are how many hours on the engine and how many hours on
> the carbs
> since a rebuild or tear down inspection? You didn't say if this is a new
> issue after many hours of run time or has been an issue up front?
>
> *The engine/carbs have 160 hours since new. No problems at all til the
> failure last week. Carbs have never been into.*
>
>
> >One last thought or maybe it should be one of the first thoughts. Do you
> have a
> recirculation line back to your gascolator or tanks. If you happen to get a
> vapor
> lock in the right place the pressure will drop to zero. These pumps can't
> pump air. The start of vapor lock will mimic these symptoms.
>
> *No return line. On the day of the failure it was about 35 degrees and
> running avgas. Had been airborne for about an hour.*
> **
> *I flew it about an hour today after checking everything. No pressure
> fluctuations or problems of any kind. Ran fine. I do believe it was the fuel
> filter now. That is the only thing I found that might have been it. The big
> thing I think I learned from this is that I don't consider it to be able to
> gravity feed as it is now. I would encourage others running high wing planes
> that you think will gravity feed in event of pump failure to check the flow
> at the carb inlets if you haven't already done so. After checking that I
> would have grounded mine if I didn't have an electric backup pump. *
> *Roger and others...thanks for all the info and I will definitely keep it
> all in mind as I try to improve the fuel system...I would like to plumb it
> w/o a low spot in the line routing but that may be difficult w/o interfering
> with the 701 door opening. Thinking.*
> *Thx again*
> *Joe*
>
> **
>
>
> *
>
> *
>
>
Message 24
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| Subject: | Re: Fuel pump failure |
Glad it is working out. Here are a few things that may help in the future just
to make your fuel delivery system a little better. Use the 5/16" line all the
way to the mechanical pump. Put in a gascolator for your low spot and you can
then take a fuel sample and check for water or other contamination plus it has
a screen in it to help filter. Run a recirculation line from the cross over
line on top of the carbs back to one of the ports on the gascolator.
--------
Roger Lee
Tucson, Az.
Light Sport Repairman - Maintenance Rated
Rotax Repair Center
520-574-1080
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http://forums.matronics.com/viewtopic.php?p=281574#281574
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