912ULS 5800rpm in WOT?

What sort of tachometer are you running?

An EIS.

Hi Matthew

If your engine has an overload clutch it may be slipping.  Given the engine hours perhaps it is in need of service?   If you think all that is good perhaps check all the EIS connections, vibration over time can cause problems and perhaps it is just a bit of extra resistance.  

Cheers

Perhaps there are other rather minor aspects the cause for the slightly increased rev (5420 to 5500). And perhaps they also caused the increase in the leveled out figures. Personally I’d keep an eye on it for a while and consider variations in OAT, humidity, FL. 80 revs does not sound a lot to me. However, one needs to notice slight changes and stay aware, for sure. My 80 horses 912 has got two faces really - summer and winter.

"Normally on takeoff I see 5420 RPM.  Tonight I had 5500, which increased to 5600 on climb-out, and it didn't stop there.  Leveling off, WOT hit 5800rpm, and I immediately pulled back."

My concern is he had to pull back to control the limit at 5800.  How far would it have gone?  The issue for me is why is the prop not loading the engine enough any longer to control overspeed?

Cheers