I am unable to start engines on prop driven aircraft, both MS Defgault and add ons such as the twin otter. Can hear turbines winding up but then just stops and starts all over. Have plenty of fuel.ThanksKevin K

It could be any number of things, but how about the magnetos? Are they on?

Load a default aircraft first, THEN load your choice of addon. Sounds like you have a saved flight with parameters that don't work with Ctrl+E and the only way to fix that if you cant identify what you've missed is to create a new save of the existing flight. You can always shut it down again before saving if you want a cold/dark situation.That said, many addon aircraft benefit from following the correct procedures, usually contained in the manual that accompanies such aircraft. Have you tried reading the manual ad starting the engines in accordance with the checklist?

Can hear turbines winding up but then just stops and starts all over. Have plenty of fuel.

fuel levers/switches on?--

This sounds a frighteningly lot like fuelmixture on lean / idle cutoff.Try moving the levers to full rich, either by mouse or CTRL-SHIFT-F4 (i think).

Load a default aircraft first, THEN load your choice of addon. Sounds like you have a saved flight with parameters that don't work with Ctrl+E and the only way to fix that if you cant identify what you've missed is to create a new save of the existing flight. You can always shut it down again before saving if you want a cold/dark situation.That said, many addon aircraft benefit from following the correct procedures, usually contained in the manual that accompanies such aircraft. Have you tried reading the manual ad starting the engines in accordance with the checklist?

I always use the correct procedures, only tried CTRL E as a last resort. I use CH Yoke and throttles, pre start up checks as per the manual. No problems with PMDG 747 or 737.Loaded a flight with single engine (C172) then change a/c type to Dash 8, right engine was running was able to manual start the left, so progress at last.Kevin

It has been happening to me also. I used to be able to do manual starts but since I added A2A Stratocruiser, manual starts in all other aircraft no longer work. I can start OK using Ctrl+E but when doing manual starts, I hear the starter spin up and N2 gets to about 22% but nothing happens after that except the starter keeps spinning the engine. The engines never light off. Plenty of fuel.

Same thing here. No matter what I did with the A2A B-17G to start it up realistically, engines #1 and #4 just went clank, clank, clank, and sputter without starting up. Only with significant intercooler and fuel mixture settings would they eventually come to life. I had to prime the two engines 7 times before they'd go. Dave.