I had throttle mixture controlled by AI set on, but some planes the revs are high all the time and in the case of the spitfire it blows engine after 3 mins in the air.

So i made it manual and i could at least turn down fuel mixture..

Is the fuel mixture what is causing high revs, or is there something else i am not getting?

Yes.  Do you have a throttle quadrant?  You need to control throttle, mixture, and prop speed - very important on this one.

If you look at the Saitek throttle on amazon (other retailers are available ) You will see there is the black throttle, blue prop speed, and red mixture levers.
It is well worth getting one of these.  Only £42.99 today UK price, and it transforms the sim for me, as prop speed and mixture are very important for lots of aircraft in the sim.

This is one of the cheaper ones, but it works alright for me.  I get much finer control, and there are extra buttons as well.

Edited November 25, 20214 yr by bobcat999

22 minutes ago, flightyjoe said:

I had throttle mixture controlled by AI set on, but some planes the revs are high all the time and in the case of the spitfire it blows engine after 3 mins in the air.

So i made it manual and i could at least turn down fuel mixture..

Is the fuel mixture what is causing high revs, or is there something else i am not getting?

1/ are you sure that the AI does a good job managing the MP ?

2/ What Bob said, in the Flyingiron Spitfire for instance , you have to reduce the rpm to 2690 (from memory, I haven't flown her for a while) pretty soon after take off except of course if you train for a dead stick landing 😈