C90 Not making full power?

Ask Questions and Offer Advice Related to the Cessna 120 & 140 Type
Forum rules
You must be a member of the Cessna 120-140 Association in order to post new topics, reply to existing topics, or search for information on this forum. Use the "Join" link in the red menu bar.
7985
Posts: 10
Joined: Tue May 01, 2018 7:00 am
Name:
Aircraft Type:
Occupation-Interests:
Contact:

Re: C90 Not making full power?

Post by 7985 »

On the takeoff run I got up to rotation speed which is about 58 mph.

I agree with the post that says you can barely get 2475 while at altitude.
I just think that at 60 mph I should be getting more than 2200.
User avatar
6643
Posts: 2609
Joined: Tue May 01, 2018 7:00 am
Name: John C
Location: KLCI, NH
Aircraft Type: 1946 C140/C90
Occupation-Interests: A&P, semi-retired
Contact:

Re: C90 Not making full power?

Post by 6643 »

7985 wrote: Sun Aug 03, 2025 9:07 am I just think that at 60 mph I should be getting more than 2200.
I'm inclined to agree with you, but without knowing the particulars of your prop and your static RPM there's no basis for making that decision.
8342
Posts: 314
Joined: Sun Oct 14, 2018 11:55 pm
Name: Rick F
Location: KUSE Wauseon OH
Aircraft Type: C-140 (sold)
Occupation-Interests: Captain B-777 (Retired)
Contact:

Re: C90 Not making full power?

Post by 8342 »

Static RPM is check with the airplane not moving.
You do this during your engine run before takeoff.
Not during takeoff.
After your magneto check, hold the brakes and push the throttle al of the way in. Now record your tach reading.
Check that number with the engine/propeller specific rpm. If it is not to specs it needs to be investigated.

Rick
Post Reply