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Couple of days ago I received the following letter. I've removed the author's name to avoid embarrasing him/her. As I'm (of course) interested in prolonging engine live, I'd like to hear your thoughts :
One of my pet peeves for a long time has been the way pilots &
instructors shutdown & start gravity feed aircraft engines. By GRAVITY
FEED, I'm refering to your vintage non-electric Taylorcraft that has no
positive mixture shut-off like modern day aircraft have. I've seen them run
the engine up, close the throttle & then turn the switch to off.
This practice gives the engine a real good fuel bath & increases wear
many fold on start up not to mention the enhancement of RUST. Many of you
understand these techniques & I invite your comments. There is no telling
how much money has been spent by owners who think they have leaky carbs all
brought on by turning their engines off with the throttle closed. There is
no way to tell how much fuel has been
wasted either.
I'm going to list a number of things here that if done will
increase the life of your engine, make starting & shutdown easier & save you
money.
Engines with mixture controls are shut down by starving the engine of fuel.
The following has been proven to work best with gravity feed engines:
1. SHUTDOWN..Close the throttle, let the engine wind down, turn
the mag switch to off & at the same time, open the throttle fully. After the
engine stops, close the throttle. This might take both hands.
2. START.. Cold or Hot. Close the throttle completely. Be sure
your prop man understands & turn the switch ON after the prop is in
position. Give the CONTACT command to the prop person. Turn the prop
until the engine starts. The engine will start exactly when it is ready
because you are primimng with the mags HOT. Have the prop person understand
that the mags are HOT from the GIT-GO without any priming and tell them to
simulate the speed of an electric STARTER. The reason for simulating a
STARTER is, with impulses on the mags, you can actually disengage the
impulses if you turn the prop too fast. Too slow is also not a good idea.
I hope this helps you prolong the life of your engine & makes
starting easier. One other thing, an ounce or two of Mystery oil in your
gas once in a while will keep your carb clean & will usually stop leaky
float valves.
One of my pet peeves for a long time has been the way pilots &
instructors shutdown & start gravity feed aircraft engines. By GRAVITY
FEED, I'm refering to your vintage non-electric Taylorcraft that has no
positive mixture shut-off like modern day aircraft have. I've seen them run
the engine up, close the throttle & then turn the switch to off.
This practice gives the engine a real good fuel bath & increases wear
many fold on start up not to mention the enhancement of RUST. Many of you
understand these techniques & I invite your comments. There is no telling
how much money has been spent by owners who think they have leaky carbs all
brought on by turning their engines off with the throttle closed. There is
no way to tell how much fuel has been
wasted either.
I'm going to list a number of things here that if done will
increase the life of your engine, make starting & shutdown easier & save you
money.
Engines with mixture controls are shut down by starving the engine of fuel.
The following has been proven to work best with gravity feed engines:
1. SHUTDOWN..Close the throttle, let the engine wind down, turn
the mag switch to off & at the same time, open the throttle fully. After the
engine stops, close the throttle. This might take both hands.
2. START.. Cold or Hot. Close the throttle completely. Be sure
your prop man understands & turn the switch ON after the prop is in
position. Give the CONTACT command to the prop person. Turn the prop
until the engine starts. The engine will start exactly when it is ready
because you are primimng with the mags HOT. Have the prop person understand
that the mags are HOT from the GIT-GO without any priming and tell them to
simulate the speed of an electric STARTER. The reason for simulating a
STARTER is, with impulses on the mags, you can actually disengage the
impulses if you turn the prop too fast. Too slow is also not a good idea.
I hope this helps you prolong the life of your engine & makes
starting easier. One other thing, an ounce or two of Mystery oil in your
gas once in a while will keep your carb clean & will usually stop leaky
float valves.
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