Plane seems to have lost some of its power

Cessna 177 (Lycoming O-320-E2D) 150 horsepower
Static RPM @ max throttle setting
Not over 2360, not under 2260
http://rgl.faa.gov/Regulatory_and_G...3634ab862577e300722423/$FILE/A13CE Rev 28.pdf

Cessna 172P (Lycoming O-320-D2J) 160 Horsepower
Static RPM @ max throttle setting
Not over 2420, not under 2300
http://rgl.faa.gov/Regulatory_and_G...754258e86257acc0077095f/$FILE/3A12_Rev_83.pdf

Piper PA28-160 (Lycoming O-320-B2B or D2A) 160 horsepower
Static RPM @ max throttle setting
Not over 2425, not under 2325
http://rgl.faa.gov/Regulatory_and_G...ea3dd6486257bb20063ad44/$FILE/2A13_Rev_52.pdf

Socata TB9 (Lycoming O-320-D2A) 160 horsepower
Static RPM @ max throttle setting
Not over ?????, not under ???????
Unfortunately the Type Certificate Data Sheet don't provide needed information.
http://rgl.faa.gov/Regulatory_and_G...f8b2e08625783a0076a6ac/$FILE/A51EU Rev 17.pdf
 
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bnt83 said:
RPM limits while on the ground, brakes locked, still air, near standard atmospheric conditions with the throttle set wide open during a ground run.
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yes,static rpm. That's what several of us have asked in this thread. Don't wonder about power, check the static rpm.

Then wonder if you have the right prop ;)
 
JHW said:
yes,static rpm. That's what several of us have asked in this thread. Don't wonder about power, check the static rpm.

Then wonder if you have the right prop ;)
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Chances of his rare imported plane being modified with the wrong prop seem pretty slim. The TCDS list several acceptable ones from the common manufacturers.
 
bnt83 said:
Chances of his rare imported plane being modified with the wrong prop seem pretty slim. The TCDS list several acceptable ones from the common manufacturers.
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it's probably modified once a year
 
weirdjim said:
If you can't see 25/50 RPM tach on a scale with 100 RPM a tenth of an inch wide, I'd worry about passing your next eye exam.

OK, for those who are already examining the timing, the carburetion, the compression, the position of the cabin heat valve ... and all the rest of it, and if you don't suspect that there is anything wrong with the tach (pretty reliable units) and IF the engine is making full static RPM with a fixed pitch prop ...

WHY WOULD YOU HAVE THE GUY DO ANYTHING ELSE? WHAT DOES THE STATIC RPM CHECK SHOW THAT FIXING THE MAGS OR THE FUEL HAVE TO DO WITH IT?

Thanks,

Jim
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With a fixed pitch prop, a static RPM check can show a loss of power over time. Of course this is reliant on tach accuracy; fuel flow, IAS, and EGT combined serve as a cross reference as well.
 
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Henning said:
With a fixed pitch prop, a static RPM check can show a loss of power over time. Of course this is reliant on tach accuracy; fuel flow, IAS, and EGT combined serve as a cross reference as well.
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Another major factor that does occasional happy is..

1- Over time in an older plane multiple prop dressings can and will reduce prop efficiency where is becomes able to produce rated static run up rpm and but moving less air...

2- Buried somewhere in a log book entry the prop was overhauled /tweaked /etc for less pitch to help in climb and that will give you the desired static rpm but not clearly show the current state of the motor since the static numbers are based on a steeper pitched prop..

In know of a couple of Cherokees that had mods done to the prop and only the owners were aware of that change.. One went to a climb setting.. / 74DM-6-058 to a 74DM-6-056 pitch.. The other one went the other way and changed it to a 74DM-6-061 for higher cruise speed at the sacrifice of climb performance.... Both planes over their life had the props sent to 2 different prop shops and neither one found that they were repitched, even though they claimed they had set them up and checked at all the "blade stations" to confirm they met OEM specs... :(
 
Not at the hangar to check, but PROPTACH bubbles up in my porous brain as the name.
 
Are you sure the carb heat is fully off when it's supposed to be off? Have had this one bite me already.
 
How would I know?

RPM def. drops when I put it on
 
dell30rb said:
I used to think a 152 was a rocket.
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First couple flights in the plane I felt the same way.
"Racing" around the pattern.

After getting my ticket and doing some 300 nm flights I was quickly thinking "Dear God this is the slowest plane in the world"

I had a tailwind once that got me up to 146kts GS.
On the way back home 47kts GS.

All we could do was laugh.
 
SixPapaCharlie said:
First couple flights in the plane I felt the same way.
"Racing" around the pattern.

After getting my ticket and doing some 300 nm flights I was quickly thinking "Dear God this is the slowest plane in the world"

I had a tailwind once that got me up to 146kts GS.
On the way back home 47kts GS.

All we could do was laugh.
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And stop for fuel...
 
Norman said:
Good point. It wouldn't hurt to take a look and see if the internal baffles are blocking the outlet.
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This happened to me. Subtle power loss ultimately found to be caused by baffles breaking loose inside the muffler, causing flow restriction.

Preflight check now includes whacking the muffler to listen for rattles.

Tim
 
Just got the results back from the compression test. Three of the four cylinders were at 50.
at least we weren't imagining it.
 
philiplane said:
A worn camshaft is the prime culprit in gradual loss of power when the compressions and all other indications are normal.
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^^^^This. Your compressions can be fine, but if the cam lobes are warn, then you are not getting appropriate valve lift. How many hours on the engine?
 
800 I think.
he said there was so much carbon buildup that the valves were not able to see properly he is in the process of cleaning them up nowvery strange because I feel like I lean really aggressivly
 
SixPapaCharlie said:
800 I think.
he said there was so much carbon buildup that the valves were not able to see properly he is in the process of cleaning them up nowvery strange because I feel like I lean really aggressivly
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Nope, you (or your dad) obviously don't.:lol:
 
I've been pretty convinced that my Flybaby doesn't climb like it used to. Discovered the timing was way off on the annual this year. Hoping that makes a difference, we shall see.
 
Plane is ready.
I don't have the vocabulary for this.

There was a hose he described as sort of a ram air hose (his words not mine) that was supposed to be attached to the carb. It was detached. If anyone knows what that is, fill me in.

He said it had a clip on it that was fastened with a screw but the screw was missing.

He fixed that, cleaned the valves, and got compression up to mid 70s on all cylinders.

Static test prior between 2350 and 2400 RPM
Static test after 2500 RPM
 
So, problem solved and got a new mx.
Just wrapped up a flight and all my power is back.

cornerstone aviation out at meechum field in fort worth.
Very pleased with quality, service, turnaround time, and price.
 
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