Hello All. First post and really hoping I can get some advice. I own a Cessna 182 RG II, fitted with an 0-540-J3C5D engine. The engine was recently overhauled, and while doing this we did all the hoses, the mags, the carb, alternator and the exhaust stacks. With it all fitted back on the aircraft I have noted a significant reduction in power, made very noticeable on the take off run. She is normally a fantastic performer but has become a real road runner.

I am getting red line on the rpm and and the map is approximately correct. However, I have noticed that the fuel flows are much higher than they used to be. I have cruised at 6000, 8000 and 10000, taking careful note of the fuel flows compared to performance charts and they actual fuel flows are consistently 20% to 30% higher than published in the POH.

You should also know that I have a JPI900 installed which allows me to carefully monitor the engine.

Any suggestions about what is going on? Please help!

Wow, very interesting. Will watch this topic with interest.

Able to achieve the same EGT/CHT at the same power and RPM as before?

Are you calculating your fuel flows from fuel used for time of flight or strictly going off of your JPI?
Also, does leaning on improve your power?

How many hours on it now, and are cruise speeds normal? RPM doesn't mean much with a constant speed prop, it should always get there unless its VERY down on power. With the dual mag, you first need to verify the timing is correct and it's working correctly, mag grounds ok at idle and can shut the engine off. The biggest deal would be if you have a cam off a tooth, that can cause issues like this. It could be running rich too, if the carb was overhauled incorrectly. Is the fuel flow reading verified by the fuel used on a flight? How are CHT readings?