The Large 2 bladed propeller won't actually start, just spin. However, using the 3 bladed propeller works, and the engine start, although it isn't enough power to fly with.

EDIT 1; Just found out it doesn't work with anything that used the Large 2 bladed propeller, such as on the PZL. I tried the latest version of the mod (14.0.0) and the same error occurred.

This is due to the engine stalling out when you start it due to it not having enough throttle at lower speeds. Seeing as how this is a common issue, I need to find a way to address it so it doesn't happen anymore. Might have to add a bit of throttle to the engine when starting or something...

Alright, thanks Mr. Bruce.

I'm going to re-open this, as it's something I need to fix. Will leave it open until fixed so others who have the same issue can see it.

Addressed in V14.2.0.