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Performance Issue

In cruise flight at 23"mp and 2300 rpm, mixture full rich fuel flow is 11gph. The aircrafts IAS seems slower by about 10kts than it was a few months ago. Also now oil temperature is fluctuating between 180 and 200 degrees, it was always stable at about 150 degrees in the past. Also I noticed at full power on take off fuel flow was only 19gph; I think it should be higher.
It seems to me that the fuel system needs to be adjust to increase flow for takeoff and cruise. Could this reduced fuel flow cause the increase in oil temperature? I'd appreciate your thoughts on this.

Model: Bonanza G33
Aircraft Serial Number: CD-1285 IO-470 N (approx 150 hours smoh)
Posted 8/15/2023 - 6 months ago
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Those fuel flows seem a bit low for a IO-470N. Since it was a change from a few months ago it could be a few things. What do your cylinder temps look like in cruise?

Posted 8/15/2023 - 6 months ago
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Continental suggests doing a fuel system setup each year. Whenever you see takeoff fuel flows starting to drop it is time to have the fuel system setup done as per the continental M-O manual.
Takeoff fuel flow on the IO470N should be between 21.1 and 22.3 GPH with throttle, prop, and mixture full forward and EGT should be around 1300F.

Bob Ripley
ABS Technical Advisor

Posted 8/15/2023 - 6 months ago
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Thanks for the suggestion Bob.

Posted 8/16/2023 - 6 months ago
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Performance Issue