Lack of power in Cessna 172-R

"G.R. Patterson III" wrote in message
...


Chuck wrote:

Also, there was a "burbling" sound from the exhaust.

Fuel spilling in. It's running way too rich.

http://www.sumpthis.com/docketno2001...617rin2120aa64
..htm

or

http://makeashorterlink.com/?K66442667

Paul

Hi, all,
First, I want to thank everyone who made suggestions.

Gary, a compression check was done on all cylinders and the
compression is fine. The power for a full-power static runup should be
2065 to 2165 with the mixture leaned for max rpm. The actual rpm is
about 2150.

No Spam, I could not get the website you gave me. Is there an
alternative one? I agree with you, 2100 rpm on the takeoff rull seems
a bit slow, but I don't know what the norm is for this plane.

Victor J. Osborne Jr., your question about fuel flow/pressure is
interesting. When starting you are supposed to advance the lean
control with the aux. fuel pump on to get about 3-5 gal/hr., then when
it starts, you turn off the aux. fuel pump. But once the engine
starts, I don't know what the fuel flow/pressure is. Do I read it on
the fuel flow gage?

Roger Long, I don't know if your "lifters" problem applies to this
plane because the cruise is fine. Just the take off and climb out is
sluggish. Since the compression is good, I'm assuming the engine is
ok. Am I mistaken?

Aaron Coolidge, your comment about the fuel injection is also
interesting. I will certainly ask our mechanic to check it (since the
plane is in for its annual anyways). I did not, however, notice loss
of power, but at minimum rpm (with the throttle full out) it does not
idle very well -- it feel like it's going to stop.

George Patterson, you say it's running way to rich. I was wondering
way you say this, but you just may be right. To correct this I


Once again, thanks to everyone.

Chuck



Freedom Chuck - The Man of 1,000 Songs

see my website at: www.freedom-chuck.com

Chuck wrote:

George Patterson, you say it's running way to rich. I was wondering
way you say this, but you just may be right. To correct this I

The "burbling" sound you report is typical of raw gas going through the engine
and igniting in the exhaust system. I'm not familiar with the injector system,
so I really can't help with troubleshooting. With a carbureted engine, you
could easily check this by leaning on the ground.

George Patterson
A diplomat is a person who can tell you to go to hell in such a way that
you look forward to the trip.

Hi, George,

Thanks again for your help. I'm going to ask my AME to check the fuel
injection system.

Chuck


On Fri, 13 Feb 2004 01:30:35 GMT, "G.R. Patterson III"
wrote:



Chuck wrote:

George Patterson, you say it's running way to rich. I was wondering
way you say this, but you just may be right. To correct this I

The "burbling" sound you report is typical of raw gas going through the engine
and igniting in the exhaust system. I'm not familiar with the injector system,
so I really can't help with troubleshooting. With a carbureted engine, you
could easily check this by leaning on the ground.

George Patterson
A diplomat is a person who can tell you to go to hell in such a way that
you look forward to the trip.


Freedom Chuck - The Man of 1,000 Songs

see my website at: www.freedom-chuck.com

Chuck wrote:

Thanks again for your help. I'm going to ask my AME to check the fuel injection
system.

You can do what you want, but I suspect that your mechanic (A&P: Airframe and
Powerplant) would know more about the fuel injection system than your physician
(AME: Aviation Medical Examiner). :-)

Russell Kent

Russell Kent wrote in message ...
Chuck wrote:

Thanks again for your help. I'm going to ask my AME to check the fuel injection
system.

You can do what you want, but I suspect that your mechanic (A&P: Airframe and
Powerplant) would know more about the fuel injection system than your physician
(AME: Aviation Medical Examiner). :-)

Russell Kent

He'll be a Canadian. An AME here is an Aircraft Maintenance
Engineer, roughly equivalent to an A&P-IA.

Dan (Canadian AME)

On Fri, 13 Feb 2004, Chuck wrote:

Victor J. Osborne Jr., your question about fuel flow/pressure is
interesting. When starting you are supposed to advance the lean
control with the aux. fuel pump on to get about 3-5 gal/hr., then when
it starts, you turn off the aux. fuel pump. But once the engine
starts, I don't know what the fuel flow/pressure is. Do I read it on
the fuel flow gage?


You leave the pump on until after starting? My 172R POH says to shut the
pump off before starting. I only use the pump for priming and switching
tanks. I also make sure to lean back a few turns as soon as the engine
settles down.

--
Rick/JYO
remove 'nospam' to reply

fuel flow/pressure. I recently learned that some add-on fuel flow
transducers can restrict fuel flow, resulting in reduced flow (actually
pressure) to the injectors. i.e. you do not develop full power on take off.

Having said (?) that, I have no idea how you would check the fuel pressure
on a 172. W/o manifold pressure at sea level, I guess you w/b left w/
installing an aux. gauge for the test.

Thx, {|;-)

Victor J. (Jim) Osborne, Jr.



take off my shoes to reply

"Chuck" wrote in message
...
Hi, all,
First, I want to thank everyone who made suggestions.

Gary, a compression check was done on all cylinders and the
compression is fine. The power for a full-power static runup should be
2065 to 2165 with the mixture leaned for max rpm. The actual rpm is
about 2150.
I think this is the most significant thing said. There is no way that the
engine should give higher revs on the static check, than on the takeoff
roll, unless something is making a 'difference' between the configuration. I
see latter, that you say you lean for the power check, but not the take-off
roll. The obvious question at this point, is what altitude the field is at?.
If it is below perhaps 3000 feet, then the difference, together with the
noise reported really solidly implies that the injection is running rich at
it's default settings. If you are higher than this, then you should really
be considering leaning for takeoff.

snipped
Aaron Coolidge, your comment about the fuel injection is also
interesting. I will certainly ask our mechanic to check it (since the
plane is in for its annual anyways). I did not, however, notice loss
of power, but at minimum rpm (with the throttle full out) it does not
idle very well -- it feel like it's going to stop.
Rich...

George Patterson, you say it's running way to rich. I was wondering
way you say this, but you just may be right. To correct this I


Once again, thanks to everyone.

Chuck
I think George has hit the nail on the head.

Best Wishes

Last summer we bought a 1997 160 HP Cessna 172-R. The test flight
(with 3 adults) went just fine.

Hi Chuck

Suggest you pull all of the plugs & examine them - I believe that you
will find at least some of them are black from running too rich.

I also suggest that you also post your question at:
http://www.cessnaowner.org/new/forum/forums.htm

There is a ton of Cessna knowledge there.

Tony


--

Tony Roberts
PP-ASEL
VFR OTT
Night
Almost Instrument
Cessna 172H C-GICE