NMPRA

Okay, so after great engine runs and responsive, consistent needling all season so far, I go up to the line for round two in the Q40 finals at the Nats and my engine won't pipe up. We get it off the ground and I flounder around for ten laps to get my point. Couldn't find anything wrong with the engine, but I swapped engines anyway. The new one came up to rpm in the pits, so out to the line we go. Set the needle right where I wanted it, launched and came around pylon 1 with the rest of the group. We were all together for about three laps, then the plane slows and the engine quits. I bring it in for a perfect landing right at my feet.

Back home, I connect some tubing to the needle valve so I can catch anything that might come out. I spray some brake cleaner into the open fitting and this black chunk of something shoots into the cup.

So now, what's anybody's thinking on in-line fuel filters? I have never run one, but am now considering.

Thanks for your input.

Tim Lampe

I ran fuel filters for nearly 15 years, never had an issue with them. Just clean them out before the race weekend and go. I don’t use them anymore, not for any particular reason.

I do filter my fuel as I pull it into my syringe.. then back flush my filter, to purge any particles that I may have picked up from the fuel bottle. Then push it in the tank.

I’ve had an issue from time to time with crystallized hard fuel deposit stuck in my FAI needles (never in Q40). So I flush those needles after weekend of use. I just pull alcohol in a small syringe and flush the needle.

Bum luck Tim.. so man!

Randy Bridge

Oh yea, the ole back-flush the fueler routine!

You know Randy, I can remember the conversation I had with Mike Helsel about this a long time ago. Although I remember the conversation, I have forgotten to implement the practice!

Hey, thanks Randy for chiming in and for your sound advice (which I will insure to practice from now on!).

Tim

I think the real issue is "NOT" allowing foreign material into the system!

Once in the system does it matter where it gets stuck, ,, In-Line Filter or needle valve?????

Prolly Not

Hi Scotty.

I would assume that if the filter traps debris, fuel may still flow (up to a point of course) because of the larger cross-section of the filter.

Tim

One thing I have noticed,,,,, If the fuel is running out the venturi when I remove the clamp and before the start,, the motor runs well!!!

Fuel filter on the airplane + drawing fuel into the fueler WITHOUT it's fuel filter in line. No need to back flush fuel from the filler back into the jug.

...and as long as I remember that you should be able to see light through the fuel filter on the airplane if you hold it up to the sky my engines needle pretty reliably

I was in the garage just back from the NAT's and had a few half empty gallons of fuel and decided to combine them.

With this "POST" in mind I snuck into the kitchen and swiped a strainer ,,, Don't tell "M" !!!!

As I combined the containers this is what the strainer caught!

Very Interesting!!!!

Man, getting a penny stuck in the needle valve would really ruin your race weekend!

Tim

Well I must admit, I did not see that one coming