Engine RPM

[robert7467]

Mooney M20C 180 HP.

Right now at full throttle RPM is 2720-2730 and redline is 2700. Will 20-30 RPM on takeoff and climb hurt the engine?

Is there an easy way to adjust it?

[fantom]

If it's really that RPM, no damage to the engine, but I'd check calibration of your tach first. It's only 1 percent.

[rob]

I agree, I'd get an optical tach on it. My tach was off by 50RPM at 2700 when I bought the plane.

[Oscar Avalle]

Yes check the tach first.

[jetdriven]

Lycoming says in its overspeed bulletin SB369J if it's a 5% overspeed (2,835 RPM) or less, correct the causes and fly on. 5-10% overspeed drain oil, check screens, borsecope,compression check, disassemble and inspect magnetos.

Over 10% (2970 RPM) for more than 3 seconds, tear down and inspect.

At high indicated airspeed in a 201 with that McCauley prop and you ram the knob forward, it is possible to overspeed the engine past 10% for 3 seconds.

[robert7467]

So, at 2720-2730 I am good to go?

[jetdriven]

Technically, no. But technically, according to Lycoming, if your timing isnt 20.00 degrees its not airworthy. Lycoming shipped mine at 22.3 degrees. its also airworthy to operate at 475 degrees CHT continuously, without limit.

I wouldnt change it. I would verify it though.

[Lionudakis]

I know of a few mooneys out there that were intentionally cranked up a few rpm's to pick up a few hp, but it doesn't make it right, or wrong. As long as it's not into the 'overspeed'. Like jetdriven said, I would verify that's actually what it is and leave it. One my prop there's a static pitch adjustment on the front of the hub, that limits the low pitch stops, checked at static rpm, once rolling or in flight the governor limits rpm.

[Magnum]

It is an easy fix at the prop governor, there is an adjustment screw for full rpm. But check the tach first.