hand-propping a 172SP

Hey guys,

I tried hand-propping a 172SP yesterday, without success. I don't have
experience of hand-propping (I was at the controls), but the guy
throwing the prop did.

I understand that it's tricky with a fuel-injected engine (which the
172SP has). Anyone have any tips on how to do it?

Tom

This may be a silly question. If you were hand proping it because the
battery was dead, was there enough battery for the fuel pump and
injectors to work?


On Mar 3, 8:53*pm, Tom wrote:
Hey guys,

I tried hand-propping a 172SP yesterday, without success. I don't have
experience of hand-propping (I was at the controls), but the guy
throwing the prop did.

I understand that it's tricky with a fuel-injected engine (which the
172SP has). Anyone have any tips on how to do it?

Tom

On Mar 3, 9:07*pm, Tina wrote:
This may be a silly question. If you were hand proping it because the
battery was dead, was there enough battery for the fuel pump and
injectors to work?

On Mar 3, 8:53*pm, Tom wrote:



Hey guys,

I tried hand-propping a 172SP yesterday, without success. I don't have
experience of hand-propping (I was at the controls), but the guy
throwing the prop did.

I understand that it's tricky with a fuel-injected engine (which the
172SP has). Anyone have any tips on how to do it?

Tom- Hide quoted text -

- Show quoted text -

Bingo! Tina, you get an A. I bet there's not enough pressure on the
injectors to spray the fuel.

Wil

On Mon, 3 Mar 2008 18:57:50 -0800 (PST), William Hung
wrote:

On Mar 3, 9:07*pm, Tina wrote:
This may be a silly question. If you were hand proping it because the
battery was dead, was there enough battery for the fuel pump and
injectors to work?

On Mar 3, 8:53*pm, Tom wrote:



Hey guys,

I tried hand-propping a 172SP yesterday, without success. I don't have
experience of hand-propping (I was at the controls), but the guy
throwing the prop did.

I understand that it's tricky with a fuel-injected engine (which the
172SP has). Anyone have any tips on how to do it?

Tom- Hide quoted text -

- Show quoted text -

Bingo! Tina, you get an A. I bet there's not enough pressure on the
injectors to spray the fuel.

The electric fuel pump is turned off before you engage the starter in
a normal start.

Still, Peter, would you not agree a dead battery would prevent a hand
propped injected engine start? You'd not be able to charge the fuel
system with the electric fuel pump, nor would the injection computer
have power to run.

If the OP was trying to hand prop an engine that just had a failed
starter motor my questions are rendered moot: he didn't tell us the
specifics, but maybe he will.






wrote:
On Mar 3, 9:07*pm, Tina wrote:
This may be a silly question. If you were hand proping it because the
battery was dead, was there enough battery for the fuel pump and
injectors to work?

On Mar 3, 8:53*pm, Tom wrote:

Hey guys,

I tried hand-propping a 172SP yesterday, without success. I don't have
experience of hand-propping (I was at the controls), but the guy
throwing the prop did.

I understand that it's tricky with a fuel-injected engine (which the
172SP has). Anyone have any tips on how to do it?

Tom- Hide quoted text -

- Show quoted text -

Bingo! Tina, you get an A. *I bet there's not enough pressure on the
injectors to spray the fuel.

The electric fuel pump is turned off before you engage the starter in
a normal start.- Hide quoted text -

- Show quoted text -

On Tue, 4 Mar 2008 07:27:21 -0800 (PST), Tina
wrote:

Still, Peter, would you not agree a dead battery would prevent a hand
propped injected engine start? You'd not be able to charge the fuel
system with the electric fuel pump, nor would the injection computer
have power to run.
If the OP was trying to hand prop an engine that just had a failed
starter motor my questions are rendered moot: he didn't tell us the
specifics, but maybe he will.






wrote:
On Mar 3, 9:07*pm, Tina wrote:
This may be a silly question. If you were hand proping it because the
battery was dead, was there enough battery for the fuel pump and
injectors to work?

On Mar 3, 8:53*pm, Tom wrote:

Hey guys,

I tried hand-propping a 172SP yesterday, without success. I don't have
experience of hand-propping (I was at the controls), but the guy
throwing the prop did.

I understand that it's tricky with a fuel-injected engine (which the
172SP has). Anyone have any tips on how to do it?

Tom- Hide quoted text -

- Show quoted text -

Bingo! Tina, you get an A. *I bet there's not enough pressure on the
injectors to spray the fuel.

The electric fuel pump is turned off before you engage the starter in
a normal start.- Hide quoted text -

- Show quoted text -


Injection computer? In a 172R/S? All there is is a completely
mechanical fuel distribution servo and a spider. As for priming the
system, wouldn't pulling through enough times make the engine driven
pump eventually suck enough gas in? I've never tried to hand prop
anything so I don't know where the process here failed.