M20F Static RPM

[TNIndy]

What should the static RPM be for a 67 model M20F? Prop is a Hartzell hc-c2yk-1bf

[David Lloyd]

About 2650.  What are you seeing?

[TNIndy]

It's been changing. 2450, 2400 and now 2300. The shop is looking at it today so we'll see what they find. It's declined the last three times we've flown

[David Lloyd]

Sounds more like a cable moving around.  A failing governor usually loses the ability to decrease speed or loss of control.

[PT20J]

There are several possibilities:

1. The tach reads low

2. The prop cable isn't reaching the stop

3. The governor is set low (it shouldn't be governing at all until there is some airspeed)

4. The prop low pitch stops are set incorrectly

5. The engine isn't putting out rated power

Skip

[blankc]

Mine only made 2350. Mess around with the gov for a while and it finally ended up being a bad cam only opening the valves half way. sad face

[Guest]

From the Maintenance manual there is no listed static rpm, however as others have noted, somewhere around 2650 static, increasing to 2700 on the take off roll.

Clarence

[Marauder]

2650 and like the good doc noted, 2700 on the roll.


Sent from my iPhone using Tapatalk Pro

[carusoam]

Welcome aboard blank!

That has to be one of the crummiest first posts ever… 

Cam lobes are important…

Engines have a hard time producing power when they can’t breath…

 

Did you get this challenge fixed already?

Or are you still searching for next steps…?  (Cut and paste this one…   )

PP thoughts only, not a mechanic…

Best regards,

-a-

[blankc]

Thanks. My overhauled engine with DLC cam is being delivered today; can't do anything with it until I get my governor back from o/h next week.  No sense to install the engine without the governor first and then fight with it to put it in next week.

[MBDiagMan]

3 hours ago, blankc said:

Thanks. My overhauled engine with DLC cam is being delivered today; can't do anything with it until I get my governor back from o/h next week.  No sense to install the engine without the governor first and then fight with it to put it in next week.

It’s outstanding that you were able to source DLC lifters.  Thanks to Aircraft Specialty’s outstanding young parts man, I got a set barely in time for reassembly.   I believe it is the next best thing to a roller cam and maybe better in some ways.