Member Updates
Steven Kleiman replied to the topic 'Cessna 172 Performance App' in the forum. yesterday

Version 3.4.0 is out. It contains support for the 172I. More importantly, it allows airspeed to be displayed in MPH for the older models.

As always, C172 Performance is available for Android and iOS mobile devices and any for any computer. See



Ed Fogle replied to the topic 'Lean of peak operation problem on IO-470' in the forum. yesterday

Thanks for the reply. I did a GAMI lean test, stress mag test and manifold test, per Savvy Aviator directions. They say a spread of up to 1 gph is acceptable for LOP and .5 gph is very good. Mine was .4 gph.

The improved atomizing is understandable for improving LOP operations. I think I need to address issues with #6 ignition. Will be sending a JPI results to Savvy Aviator and a GAMI tomorrow. Will post responses.


STEVE ELLS replied to the topic 'amp meter "bounce" while flying' in the forum. 2 days ago

Hey Joey;
I'm glad your 210 is running well.
I would start by conducting a good visual inspection of the connections at your alternator. Grab them and try to pull them loose; see if they wiggle. If that's all good, go to the voltage regulator and pull the wiring plug out of the regulator; hit the contacts with some contact cleaner.
Lastly, I would think about buying a new master/alternator switch to replace the one that's installed; especially if it's the original switch.
The original master/alternator switches are not very robust and have been the source or more than one charging system problem

Please let me know what you find


STEVE ELLS replied to the topic 'Flap failure' in the forum. 2 days ago

Hi, Uneven fuel flow from the left and right tanks is "normal" for many Cessna singles. If is caused by the design of the fuel tank venting system. Fuel is free to flow out of both banks but the flowage is complicated by the fact that the vent tube, which is located behind the upper end of the left wing strut, directs ram air into the outer end of the left fuel tank. The theory is that this positive air pressure on the left tank creates uneven air pressures between the left and right fuel tanks.
There's more to the explanation it's not abnormal. There's no evidence that this ever results in fuel that won't flow to the engine. When Cessna re introduced the 172 and 182 in 1996 and 1997, there were individual vents for each tank.

About your flaps. Before you and your mechan ic snatch off the flap motor, check to see that the connections to the switches behind the panel in the flap pre select system are tight. And that the small switches have not slid or come loose in the slots they are mounted to. I've fixed many a Cessna 182 with pre select flaps by tightening up the small screws that secure the flap position micro switches in the flap pre select system.

Let me know what you find.


STEVE ELLS replied to the topic 'Lean of peak operation problem on IO-470' in the forum. 2 days ago

Hi, If you have a fuel flow instrument, I suggest that you first go to the GAMI home page ( to download the "lean find" worksheet. Then following the instructions of flying at 65 percent power, lean the engine and not the fuel flow as each of the six cylinders peak. At 65 percent power this leaning will not harm your engine. You will then be able to derive an "EGT spread." If your EGT spread is greater than 0.2 gallons between the first and the last cylinders to peak, you need to send your GAMIjectors and your Lean Find worksheet to GAMI so they can fine tune your GAMIjectors. Once your EGT Spread is adjust to provide a 0.2 gph spread, flying LOP will be no problem.
And when your EGT Spread is 0.2 gph, there will be no need to feather your throttle to achieve smooth engine operation.

Feathering the throttle (pulling it back slightly from WOT) creates additional turbulence in the induction system downstream of the throttle butterfly. Feathering the throttle is a well understood method of further atomizing the fuel metered into the airstream by a carburetor. But your IO-470 doesn't have a carburetor.

You need to determine what's going on with #6 cylinder. It could be an induction leak; it surely sounds like your EGT probe is either bad, or there's a loose or faulty connection between the probe and the gauge.

Fix whatever's going on with #6; then fix the probe. Once those problems are sorted out, do the GAMI Lean Find test and get your GAMIjectors tuned up and you'll be flying behind a smooth running engine that's safe to fly LOP.

If there's only a 1.2 inches of MAP drop through your induction system it's in good shape.

Please post what yoiu find on this forum so we can all learn.


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