Starting new C172s

I have flown it 6~7 times now, and still find starting the engine of
new Cessna 172S quite tricky, and often I have to try two or three
times to start it. I never had problem in older C172s.

So what's the trick, guys? How much throttle (1/8, 1/4 or 1/2 inch) do
you open? How fast do you advance the mixture when the engine starts to
fire? Anthing else?

Thanks

Well I think each airplane is slightly different.

However I fly most the newer 172SP, and what I have found is that you
need to prime (Fuel pump on, mixture rich) for a little longer than
what the POH specifys. Otherwise it just cranks, and cranks while of
course the fuel that was there to prime it is now gone, so you restart
the process but this time you use even less prime because you think you
have primed plenty the first time. Which makes the issue worse. Also
make sure you have 1/4 throttle, any less and it may be have enough to
get it going. As far as when to advance the mixture.... As soon as it
first starts to catch, advance it in all the way, rather quickly but
smoothly.

One thing you DO NOT want to do (I learned this the easy way, by
watching my instructor do this) is pump the throttle open and close to
force prime it. We (rather he) tried this method and we started
smelling fuel, we got out and saw a puddle of fuel near the front
wheel. We waited 5 mins and it finally started.

Having three hands helps a bit.

WBR

"navghtivs" wrote in message
oups.com...
I have flown it 6~7 times now, and still find starting the engine of
new Cessna 172S quite tricky, and often I have to try two or three
times to start it. I never had problem in older C172s.

So what's the trick, guys? How much throttle (1/8, 1/4 or 1/2 inch) do
you open? How fast do you advance the mixture when the engine starts to
fire? Anthing else?

Thanks

navghtivs wrote:
I have flown it 6~7 times now, and still find starting the engine of
new Cessna 172S quite tricky, and often I have to try two or three
times to start it. I never had problem in older C172s.

So what's the trick, guys? How much throttle (1/8, 1/4 or 1/2 inch) do
you open? How fast do you advance the mixture when the engine starts to
fire? Anthing else?

Thanks

I prime it per the manual, then start it with the throttle closed. If
it does not start immediately, I crack the throttle ever so slightly,
leave the fuel pump on, and start it. If the engine tries to die after
starting, I leave the fuel pump on until it warms up. Pretty much all
of this can be found in the manual.

Most people who have trouble starting C172s have tried to learn to
start the airplane by using the checklist without first gaining a
thorough understanding of what the manual says. There are way too many
instructors who fall into that category.

On 5 Sep 2005 08:40:45 -0700, "navghtivs"
wrote:

I have flown it 6~7 times now, and still find starting the engine of
new Cessna 172S quite tricky, and often I have to try two or three
times to start it. I never had problem in older C172s.

So what's the trick, guys? How much throttle (1/8, 1/4 or 1/2 inch) do
you open? How fast do you advance the mixture when the engine starts to
fire? Anthing else?

Thanks


I rent from a Cessna dealer FBO at VNY. The procedure there is:

Throttle - open 1/4 inch
Mixture - Idle Cutoff
Propeller area - Clear
Master Switch - ON
Beacon - ON
Aux Fuel Pump - ON
Mixture - Advance full - 2 to 3 seconds, then return to Idle Cutoff
Aux Fuel Pump - OFF
Ignition - START
Mixture - Advance full, when engine fires

Works every time for me.

BTW... same procedure when the engine is hot - EXCEPT - Mixture -
advance full - 1 second, then return to Idle Cutoff.

Ron Kelley

I've flown about 25 different 172SP's, and they've all behaved exactly
the same.

I open the throttle about an inch, and do the rest exactly by the
checklist. The only important variables seem to be:

- Make as little delay as possible between priming and turning the key
to START. It doesn't need to be immediate, but don't delay
unneccessarily.

- Advance the mixture from IDLE CUT OFF to RICH within a second or so.

OP wrote:
I rent from a Cessna dealer FBO at VNY. The procedure there is:

Throttle - open 1/4 inch
Mixture - Idle Cutoff
Propeller area - Clear
Master Switch - ON
Beacon - ON
Aux Fuel Pump - ON
Mixture - Advance full - 2 to 3 seconds, then return to Idle Cutoff
Aux Fuel Pump - OFF
Ignition - START
Mixture - Advance full, when engine fires

Works every time for me.


I take it from the procedure the new 172s are fuel injected?



--
Mortimer Schnerd, RN

VE

In article . com,
says...


I prime it per the manual, then start it with the throttle closed. If
it does not start immediately, I crack the throttle ever so slightly,
leave the fuel pump on, and start it. If the engine tries to die after
starting, I leave the fuel pump on until it warms up. Pretty much all
of this can be found in the manual.

Most people who have trouble starting C172s have tried to learn to
start the airplane by using the checklist without first gaining a
thorough understanding of what the manual says. There are way too many
instructors who fall into that category.



Following the checklist to the letter works best for most users. The above
method requires three hands, because the throttle is closed, which gives
you one extra thing to do when it fires. Whatever works best for you is
fine - but the checklist method, if followed exactly, works every time.

G Faris

In article ,
says...


I rent from a Cessna dealer FBO at VNY. The procedure there is:

Throttle - open 1/4 inch
Mixture - Idle Cutoff
Propeller area - Clear
Master Switch - ON
Beacon - ON
Aux Fuel Pump - ON
Mixture - Advance full - 2 to 3 seconds, then return to Idle Cutoff
Aux Fuel Pump - OFF
Ignition - START
Mixture - Advance full, when engine fires

Works every time for me.

BTW... same procedure when the engine is hot - EXCEPT - Mixture -
advance full - 1 second, then return to Idle Cutoff.



Pretty close to the standard method - but why use a "timed" method to
determine fuel flow from the pump, when there is an instrument in front
of you that gives precise information? If you didn't have a fuel flow
guage, or suspected that it wasn't working, this would be a good backup
method - but on the ones I've flown this guage is always working, and
gives a reliable indication for the starting procedure.

G Faris

In article ,
ve says...



I take it from the procedure the new 172s are fuel injected?




They are - and in these discussions (this is the second time this has
come up recently) we should start saying "Injected 172's" instead of
"new" - because some of these "new" models are getting to be eight or
nine years old now . . .

G Faris