Fuel filter inspection tips

[ls6pilot]

CTSW was running rough when in route climb so I landed at a nearby airport. There was some jump in the car bowls which I cleaned there was minimal debris in the gascolator  which I removed and cleaned the screen. Tested fuel flow From both tanks and it is way down. Next step I expect is to check the fuel filter. I have located it but need some tips for removing and inspecting as I have not done that before. Appreciate any advice that comes my way. Thanks guys

[Tom Baker]

It depends a little on how it is installed and the aircraft equipment, and if the firewall blanket installation was properly performed.

[ls6pilot]

Pic from left panel access sorry the pic rotated 

[Tom Baker]

You can send me your telephone number and when a good time to call is, and I will give you a call. I can't see enough detail about the installation to make a suggestion on how to proceed. 

[ls6pilot]

Thanks Tom for the offer sent you a PM last night

I managed to get the fuel filter out.   . It had a small amount of debris. Cleaned and replaced. Still very low fuel flow. Wondering if there is a way to detect if the obstruction is between the fuel filter and gascolator or between tanks and fuel filter. Appreciate advice on next steps as I am somewhat stranded at a small airport. Thanks

[sandpiper]

Very low fuel flow? Is this from your instruments? Or did you open the gascolator and measure it. Chapter 6 of the maintenance manual tells how to do this but it involves draining the tanks, putting in a minimum amount to one tank, etc, etc. In this test they call for a flow of about 0.58L per minute or 35L/hour.

Being away from home you probably don't want to do this unless you have to. So, do a quick check. Mine, with between 15-20 gallons total aboard, will give me a liter in 37 seconds +/-. Try it to see what you get. If you don't get about what I am getting then you may need to dig deeper.

Tom, if this isn't a good idea please chime in and correct me. Thanks.

[Tom Baker]

48 minutes ago, sandpiper said:

Very low fuel flow? Is this from your instruments? Or did you open the gascolator and measure it. Chapter 6 of the maintenance manual tells how to do this but it involves draining the tanks, putting in a minimum amount to one tank, etc, etc. In this test they call for a flow of about 0.58L per minute or 35L/hour.

Being away from home you probably don't want to do this unless you have to. So, do a quick check. Mine, with between 15-20 gallons total aboard, will give me a liter in 37 seconds +/-. Try it to see what you get. If you don't get about what I am getting then you may need to dig deeper.

Tom, if this isn't a good idea please chime in and correct me. Thanks.

We talked this morning, and he said he was only getting around 3 GPH measured with the gascolator bowl removed. That is not enough to run at full power. He was going to pick a point up stream and check flow there.

[sandpiper]

57 minutes ago, Tom Baker said:

We talked this morning, and he said he was only getting around 3 GPH measured with the gascolator bowl removed. That is not enough to run at full power. He was going to pick a point up stream and check flow there.

Right. That 35L/hr is 9.5 gph according to the book. Kinked or collapsed hose? If it is the tank filters it would be unusual for both to be clogged I would think. Hope someone didn't put something in his tanks.

[Tom Baker]

2 hours ago, sandpiper said:

Right. That 35L/hr is 9.5 gph according to the book. Kinked or collapsed hose? If it is the tank filters it would be unusual for both to be clogged I would think. Hope someone didn't put something in his tanks.

With the fuel flow I normally see around 20 GPH when draining fuel through the quick drain.

[MEH]

Just a thought. Try the fuel flow measurements with the gas caps off.  If the vent lines are full of fuel it may impede air inflow??? I am convinced that vent lines containing fuel are a factor in why gas tanks don't equalize their levels overnight.

If there is a change in fuel flow with the gas caps off try taking the gas caps off and blowing with your mouth in the vent hole at each wing tip to clear the fuel out of the vents. Definitely don't want to pressurize your tanks so take the caps off while you blow.

[Tom Baker]

30 minutes ago, MEH said:

Just a thought. Try the fuel flow measurements with the gas caps off.  If the vent lines are full of fuel it may impede air inflow??? I am convinced that vent lines containing fuel are a factor in why gas tanks don't equalize their levels overnight.

If there is a change in fuel flow with the gas caps off try taking the gas caps off and blowing with your mouth in the vent hole at each wing tip to clear the fuel out of the vents. Definitely don't want to pressurize your tanks so take the caps off while you blow.

The CTSW doesn't have vent lines. The vents are stand pipe in the caps.

[ls6pilot]

Turns out the obstruction was at the fuel cutoff valve. Bypassed it,got it home. More info to follow.

[sandpiper]

5 minutes ago, WmInce said:

Good catch!

Looking forward to your follow-up report.

x2

[ls6pilot]

debris in fuel cutoff valve. 

Mr. Funnel. My new best friend. 
 

[sandpiper]

That is an amazing amount of debris! I wonder what might be in the tank filters? Might be worth a look.

Thank you for posting. All of us have learned something.

[Tom Baker]

For future reference you can remove the little clip and remove the socket from the ball on the valve. 

[Tip]

I have seen that fuzz in the filter screens before. Your valve has probably been collecting it since new. I found the Mr. Funnel to be a pain. It doesn’t drain out completely and that little quantity of gas makes a mess.

[ls6pilot]

1 hour ago, WmInce said:

Thanks for posting that picture.

Those larger chunks of debris resemble the material which lines the fuel tank. Could that be possible? Debris may have been in that valve for a long time. If that's the case, Mr. Funnel would Have been of no help.

would be nice to know the composition and origin of the debris pictured.

Again . . . good catch!

It could be possibly from the tank itself. Any ideas on how to analyze the debris?  If it is coming from the wing tanks does that need to be addressed? 

Thanks

[MEH]

The first time I inspected my in-line filter there was a bunch of fiberglass fuzz and some debris.  I suspect this was from the manufacturing process of drilling the bung and other holes without meticulous cleanup.  Tip has fished out the round cut-out from one of his tanks that was generated when Flight Design cut the fueling hole. Not sure their QA is that good with regards to cleanup of the tanks. My tanks have made no debris in the two years since the initial in-line filter clean out.

 

 

[Ben2k9]

We are dealing with this right now too. One of our members lost a good amount of power on a recent flight. We cleaned out debris from a few different points: gascolator, fuel filter. We are suspecting contaminated fuel but no conclusion yet. 

[Warmi]

14 hours ago, ls6pilot said:

debris in fuel cutoff valve. 

Mr. Funnel. My new best friend. 
 

 

Last year in Feb I found a lot of rust in the gascolator . It was not the gascolator itself rusting , just very fine rust contamination for fuel. I have bee using Mr Funnel since then and this year the gascolator was 100% clean ( still using the same fuel sources )

 

[ct9000]

On 5/6/2020 at 10:06 AM, Tip said:

I have seen that fuzz in the filter screens before. Your valve has probably been collecting it since new. I found the Mr. Funnel to be a pain. It doesn’t drain out completely and that little quantity of gas makes a mess.

The reason the Mr Funnel does not drain out completely is because the bottom section is actually a water sump and so is necessary for the correct function of the filter / water separator.  I am a big fan of the Mr Funnel and use it all the time even to fuel from a bowser or to transfer from fuel can to can. Each time you use it you should check the remaining fuel in the bottom foe water droplets, it is not just a filter but will also filter out suspended moisture.

[John Vance]

Prior to making a couple of changes in operating & maintaining my CTLS, I experienced a couple of partial power loss incidents. I’ve since found that corrosion products originating in the carb bowls can plug your jets.  Below is a link to the Kathryn’s Report covering the investigation into the 2016 fatal accident that occurred at Fond du Lac.  Read especially the section on the carburetor inspection.  This is an extreme case, but it’s an eyeopener.  I’ve found the same phenomenon in both carb bowls of my airplane, but to a much lesser extent. These days, I inspect & clean the bowls every 3 months and have begun limiting ethanol, and the engine never misses a beat.  At some point, I may replace the bowls since the “black areas” seem to breed this stuff, but the cleaning regimen isn’t a big deal.  

http://www.kathrynsreport.com/2016/07/flight-design-ctls-accident-occurred.html

[GrassStripFlyBoy]

I've been burning rec gas 91 which is available at airport not far from home base, and with recent auto fuel prices as low as they are, recently considered buying 93 auto.  Filled a couple jugs last week at local station, tested and seeing perhaps 1-2% ethanol amount, have yet to pour in the CT.  This has me thinking I'll stick with the non-ethanol fuels.  With all of the oil capacity we have these days, I wish ethanol would be axed from entire supply channel.  I love farmers but can't stand what ethanol has done to harm things, boat motors, etc.

[AGLyme]

When I first joined the forum and acquired the plane, I was an idiot on gas.  My position in the early days was to buy 100LL at the airport, thereby supporting the airport and bite the bullet on the oil changes.  An A&P pal told me that auto gas fumes in a hot hangar is a nightmare.  It isn't.  And several forum members told me that.

I went to "Rotax School" a year ago and learned that the 93 auto, e-10 gas available at nearby gas stations is "thumbs up" according to the Rotax pros.  And that is what I have been burning ever since.