Cleaning your engines after running

Should I clean them? Yep. Do I clean them? Nope, not at first... Has this bitten me? Yep!

The last time it came back to haunt me was with a certain gentleman's gifted 4 foot beast of a plane with a Fox .35. After several (Several!) bench runs for break-in and understanding, the engine made it's way to the airframe. A new tank was plumbed, and ground runs performed. Keep in mind this was last winter into last summer. The engine ran...the plane was set up reasonably well for initial flights. Then early last fall I had a sparkling, cool Saturday am with zero wind and no other plans. Off to the field I went after re-arranging the back end of my Focus for the large bird. I took about 6 ounces of fuel hoping for a quick ground run and a quick test hop, and promptly ran into an engine that would NOT run behind a prime. After 20 minutes of fingering the prop I began troubleshooting. At the thirty minute mark I pulled the needle, capped the vent lines, and gave the plastic tank a good squeeze and got ZERO fuel. Nada!

By 35 minutes I had the fuel line disconnected, the needle out, and my syringe full of fuel in order to pressure-blast a gooey, stuck up spray bar. Eureka! The spraybar was cleared.

So I reconnected the tank, re-inserted the needle and hooked up the tank line. The engine ran, and needled well...lean, rich, lean as I twiddled the needle. By the one hour mark I felt comfortable enough with the ground run. By then, I had about 2.5 ounces of fuel left...ok, enough for a short flight.

I'd like to say I flew that day...but that is a different story about maintenance and knowing your equipment and supplies.

Short answer, now I wipe off the goo and flush the NVA clear with straight methanol. Metal tanks get sucked empty, but I don't flush because I want to.minimize rust. I roll the engine over to clear the methanol out of the venturi/block and use Marvel Mystery Oil or ATF to wet the engine inside (several drops). A final wipe down keeps the red stuff from dripping all over. Next start will be preceded by another methanol flush, followed by a "no glow prime and wind" to expunge the red stuff. So far, no more plugged NVAs, no significant dust glued to the exterior, and no more forcing the engine to clear itself of dried castor.

Why do I do this? So paragraph 1 never happens again. I lost a beautiful morning of flying. So I called Santa Phred and he cajoled/consoled me while telling me I should know better. Sometimes it takes a battle-buddy maintainer to say "Dude, you screwed your own maintenance program." Yep...I knew better!

Hi chevyiron420, (nice handle ! )

Frugal? I run my .049s out dry. If I am not going to run them for a while, I put a few drops of ATF (AutomaticTransmissionFluid)
in it and flick it it over a few times. Good to go.

Windshield washer fluid (I like the blue) is great for cleaning planes.
I have friends,
Who basicly towel/ rub/wax their planes with the castor oil...
They call it patina...
Take care,
Have fun,
Dave