Question: I'm having a VOR not working.

Answer: Most likely an electrical function.  Check the electrical section of the aircraft configs for each aircraft and compare them.


Question: The RPM gauge doesnt reflect changes right away.

Answer: Not really sure, but it seems to me that this is most likely an issue that you haven't encountered because of the TYPE of aircraft your flying.  If its an older engine type (WWII fighter, bomber, civilian aircraft before 1970ish) then the rev-up might be very slow.


Question: HSI starts crooked at beginning of flight, yet as soon as I rev. the engine up it goes back to horizontal.

Answer: I don't know what you've been flying, but as far as I can remember, everything I ever fly that has an analog HSI does this.  It's simply that way when you turn off the engine.  If you want it to remain straight and level, cage it before you switch the engine off.