Yak 3 engine won't start. Help me out.
 

On the single missions--USSR--Yak 3R: my engine won't start with the "I" key or any other key. On any other mission "I" starts my engine. My Yak 3 just sits there blocking the runway with a dead engine. What am I doing wrong??

Afaik one must choose "engine 1" and start it then choose "engine 2" and start that.

Engine 1: VK-105PD
Engine 2: RD-1

Have you tried filling up the tank first?;)

Flyingbullseye

The Yak 3 is single engine, so why engine 1 and 2? I totally don't understand the VK-105PD and RD-1. What's that?

Sorry I'm only a few weeks into this sim, so there is much I don't know yet.

It sounds like you may have selected "Engine 1" in the "select engine" section, if so go back up about two sections in the "control" panel, there you will find "Toggle Engine", select that as "I" that should fix your problem. I don't have the problem you have and that is my engine start setting.

The Yak-3R has 2 (Two) engines, a 12 cylinder which drives the prop and a rocket engine for additional thrust.