Carb line leaking fuel

H. Paul Shuch is a Light Sport Repairman with Maintenance ratings for airplanes, gliders, weight shift control, and powered parachutes, as well as an independent Rotax Maintenance Technician at the Heavy Maintenance level. He holds a PhD in Air Transportation Engineering from the University of California, and serves as Director of Maintenance for AvSport of Lock Haven.

Moderator: drseti

User avatar
ShawnM
Posts: 306
Joined: Sat Nov 11, 2017 9:59 pm
Location: Clearwater, FL / KZPH

Re: Carb line leaking fuel

Postby ShawnM » Mon Oct 01, 2018 12:02 pm

As always, thanks for your insight Roger. The fuel injection hose clamps are what I use and I've never had any issues in 5 years. The sad part is that my airplane manufacturer STILL TODAY uses serrated worm drive clamps on oil and fuel lines. :shock:

I like the Oetiker clamps but they are one time use clamps. The fuel injection clamps with some torque seal will last a very long time and I can reuse them if needed. :D

roger lee
Posts: 747
Joined: Tue Dec 08, 2009 11:47 am
Location: Tucson, Az. Ryan Airfield (KRYN)

Re: Carb line leaking fuel

Postby roger lee » Tue Oct 02, 2018 9:32 am

Roger Lee
Tucson, Az.
LSRM-A, Rotax Instructor & Rotax IRC
(520) 574-1080 (Home) Try Home First.
(520) 349-7056 (Cell)

User avatar
ShawnM
Posts: 306
Joined: Sat Nov 11, 2017 9:59 pm
Location: Clearwater, FL / KZPH

Re: Carb line leaking fuel

Postby ShawnM » Tue Oct 02, 2018 10:16 am

Yes, I forgot about that article Roger and I even have it bookmarked on my pc.

In doing research for hose when I did my last 5 year rubber in 2013 I chose the Gates Barricade fuel lines. It's the best hose for all types of fuels in my opinion and very affordable. I was able to buy all I needed from my local O'Reilly Auto Parts. This hose along with the stainless steel fuel injection hose clamps is a great solution for any E-LSA aircraft.

Warmi
Posts: 618
Joined: Sun Oct 16, 2016 5:35 pm
Location: Frankfort, IL

Re: Carb line leaking fuel

Postby Warmi » Wed Oct 03, 2018 10:09 pm

Got the fuel line all fixed up and good.

Another problem though - this ownership thing is getting expensive :D

Last year my mechanic installed this Curtis quick drain oil valve. I used it twice to change the oil but noticed that after the last change, it developed a small oil leak. It got worse over time so I decided to take the tank apart, disassemble the valve ,replace both crushers which I thought was the problem to begin with.
Unfortunately, after reassembling the whole thing and torquing to 70 inch/lbs ( as per Curtis specs) the leak actual got worse and it is coming (and looks like it was coming all along ) directly from the safety wire hole ( as pictured via the arrow) - I am positive this is not the valve that's leaking but the tank itself ( via the safety hole )

Frankly, when I look at it the whole assembly is a bit crooked which leads me to believe at some point , someone damaged the plug assembly itself ( not sure how - over-torquing ?) and now it is just getting worse and worse.

Has anyone seen this sort of failure and is replacing the whole tank the only solution here ?
Also , if replacing the tank , are there any special procedures to be follow or is it like a regular oil change , just with a new tank ?
Thanks
Attachments
oil_plug.jpg
oil_plug.jpg (54.48 KiB) Viewed 367 times
Flying Sting S4 ( N184WA ) out of Illinois

User avatar
drseti
Posts: 5804
Joined: Sat Nov 28, 2009 6:42 pm
Location: Lock Haven PA
Contact:

Re: Carb line leaking fuel

Postby drseti » Thu Oct 04, 2018 6:24 am

Whether with or without the quick-drain (and with or without a leak), wrinkling or crookedness at the bottom of the oil tank is indicative of someone torquing the bolt or plug without putting a protective counter-torque wrench on the facing hex head welded to the tank. This is common enough that it's one of the things I check during a Rotax pre-buy.

Replacing an oil tank is no different from reinstalling one after it has been removed for cleaning and de-sludging. As a precaution, I like to do an oil system purge after the tank had been removed, just to get air out of the system.
The opinions posted are those of one CFI, and do not necessarily represent the FAA or its lawyers.
Prof H Paul Shuch
PhD CFII DPE LSRM-A/GL/WS/PPC iRMT
AvSport LLC, KLHV
fly@AvSport.org
AvSport.org
facebook.com/SportFlying
SportPilotExaminer.US

Warmi
Posts: 618
Joined: Sun Oct 16, 2016 5:35 pm
Location: Frankfort, IL

Re: Carb line leaking fuel

Postby Warmi » Thu Oct 04, 2018 11:11 am

Looks I will have to replace the bottom oil tank assembly.
I have the metrics version of the tank , but I believe the bottom assembly is universal and the only difference between UNF and metric is in the top fittings.

Thanks again for your help.
Flying Sting S4 ( N184WA ) out of Illinois

3Dreaming
Posts: 2345
Joined: Sun Jan 10, 2010 6:13 pm
Location: noble, IL USA

Re: Carb line leaking fuel

Postby 3Dreaming » Thu Oct 04, 2018 12:18 pm

I was going to try and give you a part number, but I don't see an individual part number for just the tank. I hope that it is not the case, but you might have to buy the whole assembly.

Warmi
Posts: 618
Joined: Sun Oct 16, 2016 5:35 pm
Location: Frankfort, IL

Re: Carb line leaking fuel

Postby Warmi » Thu Oct 04, 2018 12:22 pm

I called them and indeed you can’t get just the bottom part. I have to buy the whole oil tank assembly.
Flying Sting S4 ( N184WA ) out of Illinois

User avatar
dstclair
Posts: 1029
Joined: Thu Mar 06, 2008 11:23 am
Location: Allen, TX

Re: Carb line leaking fuel

Postby dstclair » Thu Oct 04, 2018 12:28 pm

Warmi -- I'd suggest not putting the quick drain valve back on your new oil tank unless you always run unleaded. If you run more than a trivial amount of 100LL, you'll want to pull the tank off each oil change and get rid of the lead sludge.
dave

User avatar
drseti
Posts: 5804
Joined: Sat Nov 28, 2009 6:42 pm
Location: Lock Haven PA
Contact:

Re: Carb line leaking fuel

Postby drseti » Thu Oct 04, 2018 1:06 pm

I concur with Dave. I seem to recall that, in one of my Rotax maintenance classes, it was stated that Rotax does not even authorize quick-drain valves (although in the Experimental world, anything goes...)
The opinions posted are those of one CFI, and do not necessarily represent the FAA or its lawyers.
Prof H Paul Shuch
PhD CFII DPE LSRM-A/GL/WS/PPC iRMT
AvSport LLC, KLHV
fly@AvSport.org
AvSport.org
facebook.com/SportFlying
SportPilotExaminer.US

Warmi
Posts: 618
Joined: Sun Oct 16, 2016 5:35 pm
Location: Frankfort, IL

Re: Carb line leaking fuel

Postby Warmi » Thu Oct 04, 2018 1:19 pm

Yeah, I am debating it myself.

On one hand it is mighty convenient to use the valve since it is much faster than unhooking the tank etc ...
I run 100LL maybe 10-15% of time - the rest is split between 91 unleaded and Swift fuel so I am good on that front.

What worries me is that I don't see that valve on the list of approved equipment (provided by the dealer) and I am afraid it was just my mechanic who kind of "decided" on its own to add it to the list of approved equipment :-)
As I mentioned all of that happened during last years 5 year rubber job and at that time I had no idea about anything ( a few months after I bought the plane.)
Flying Sting S4 ( N184WA ) out of Illinois

User avatar
drseti
Posts: 5804
Joined: Sat Nov 28, 2009 6:42 pm
Location: Lock Haven PA
Contact:

Re: Carb line leaking fuel

Postby drseti » Thu Oct 04, 2018 1:29 pm

Warmi, unless your plane is registered as an ELSA, if the quick drain was not on the plane as it came from the factory, adding one requires a Letter of Authorization from the airframe (not engine) manufacturer. Also a logbook entry indicating that the alteration was performed, by whom, and in accordance with what specific LoA. If you have an SLSA, but no such logbook endorsement and LoA, you should immediately instruct the mechanic who installed it to remove it, at no cost to you, and to reimburse you for whatever you were charged for it, because it is an illegal modification.
The opinions posted are those of one CFI, and do not necessarily represent the FAA or its lawyers.
Prof H Paul Shuch
PhD CFII DPE LSRM-A/GL/WS/PPC iRMT
AvSport LLC, KLHV
fly@AvSport.org
AvSport.org
facebook.com/SportFlying
SportPilotExaminer.US

User avatar
ShawnM
Posts: 306
Joined: Sat Nov 11, 2017 9:59 pm
Location: Clearwater, FL / KZPH

Re: Carb line leaking fuel

Postby ShawnM » Thu Oct 04, 2018 3:00 pm

Paul is once again correct, the quick drain on a S-LSA is not legal if the manufacturer didn't install it.

When I bought my plane it was S-LSA and it had the Saf Air quick drain on it which was done illegally as there was no LOA or even a log entry for it. I've since converted to E-LSA so no issues there. I love the Saf Air quick drain that I have and would never remove it. When it's time for an oil change I simply slip a 3/8 hose over the end of the valve, place the other end in my oil drain pan, push and turn and voila, the oil flows out quickly and no crush washers or safety wire to replace. I only run 93 oct MOGAS so no need to remove the tank for lead sludge. :P

That being said, the Saf Air M12175 that is on my plane IS actually certified by Rotax for installation on their CERTIFIED engines, not the ULS. There is a FAA-PMA for the Saf Air quick drain. This gives me piece of mind knowing that if Rotax approves it for their certified engines, it's good enough for my non-certified, E-LSA 912ULS. :D

The FAA-PMA letter states that the Saf Air M12175 is an approved replacement on CERTIFIED engines for part number 241 403, which is the Rotax oil can drain plug.

Lockwood sells the Saf Air quick drain for $43.95 and the OEM bolt and crush washer total $41.36.

As you said before Warmi, if you want it done right.............

3Dreaming
Posts: 2345
Joined: Sun Jan 10, 2010 6:13 pm
Location: noble, IL USA

Re: Carb line leaking fuel

Postby 3Dreaming » Thu Oct 04, 2018 5:04 pm

ShawnM wrote:Paul is once again correct, the quick drain on a S-LSA is not legal if the manufacturer didn't install it.

When I bought my plane it was S-LSA and it had the Saf Air quick drain on it which was done illegally as there was no LOA or even a log entry for it. I've since converted to E-LSA so no issues there. I love the Saf Air quick drain that I have and would never remove it. When it's time for an oil change I simply slip a 3/8 hose over the end of the valve, place the other end in my oil drain pan, push and turn and voila, the oil flows out quickly and no crush washers or safety wire to replace. I only run 93 oct MOGAS so no need to remove the tank for lead sludge. :P

That being said, the Saf Air M12175 that is on my plane IS actually certified by Rotax for installation on their CERTIFIED engines, not the ULS. There is a FAA-PMA for the Saf Air quick drain. This gives me piece of mind knowing that if Rotax approves it for their certified engines, it's good enough for my non-certified, E-LSA 912ULS. :D

The FAA-PMA letter states that the Saf Air M12175 is an approved replacement on CERTIFIED engines for part number 241 403, which is the Rotax oil can drain plug.

Lockwood sells the Saf Air quick drain for $43.95 and the OEM bolt and crush washer total $41.36.

As you said before Warmi, if you want it done right.............


A couple comments.

First, even if you only run auto fuel, sludge still builds up in the tank. It is just not the grey pasty stuff. I clean tanks annually.

Second is Rotax does not approve the quick drain valve on the certified engines. The PMA is issued by the FAA to the manufacture of the drain valve. Rotax has no say in the matter.

Warmi
Posts: 618
Joined: Sun Oct 16, 2016 5:35 pm
Location: Frankfort, IL

Re: Carb line leaking fuel

Postby Warmi » Thu Oct 04, 2018 8:47 pm

On the oil purge question ...

Do I need to inspect the valve tappets after the purge the way Rotax Owners video is suggesting or is it something done on the new engine only ?
Flying Sting S4 ( N184WA ) out of Illinois


Return to “Ask The Mechanic”

Who is online

Users browsing this forum: No registered users and 2 guests