Lean 2 & 3 Cylinders

How to keep the Cessna 170 flying and airworthy.

Moderators: GAHorn, Karl Towle, Bruce Fenstermacher

Post Reply
N2830C
Posts: 23
Joined: Thu Aug 07, 2003 4:52 am

Lean 2 & 3 Cylinders

Post by N2830C »

I have owned my 54 170B for all of 6 months now and I just went through my first annual on it. When the plugs were pulled it appeared that the #2 & #3 cylinders were running lean while my other cylinders were running rich. Is this common for a O-300? Any suggestions?
Top
User avatar
GAHorn
Posts: 21290
Joined: Fri Apr 12, 2002 8:45 pm

Post by GAHorn »

In a healthy C-145/O-300, the number 2 cylinder runs the leanest/hottest. That's why the CHT probe is installed on that cylinder, and it's why that cylinder's exhaust is the recommended location for a single-probe EGT. If other cyls seem to be running excessively lean (or leaner than #2) you might want to investigate possible intake/induction air leaks in that cyl's induciton system. Dry;loose hoses or broken gaskets are most likely.
Top
Post Reply

Return to “The Hangar”

Cessna® is a registered trademark of Textron Aviation, Inc. The International Cessna® 170 Association is an independent owners/operators association dedicated to C170 aircraft and early O-300-powered C172s. We are not affiliated with Cessna® or Textron Aviation, Inc. in any way.