Can't get enough thrust to get our Bob Cat plane flying. We are using a 60 2 stroke engine with a 12x6 prop. Do we go up or down in size and pitch to increase thrust?
Thanks for the Information.

Pat

Be sure you are using a "pusher" prop and it isn't on backward.

Jim

Ditto... makes a huge difference if you have it on backwards. Make sure the flat side of the prop is to the rear of the plane. Biggest mistake is putting it towards the rear of the engine.

Another big ditto. I have seen this happen all too many times.

Look at the prop.

Determine which side is the front and which is the rear (You used to be able to say that the side with the lettering was the front, but some companies are now printing the rear side)

Once you have determined which side is the front, install the prop with that side facing the engine (Which is opposite to the way you would normally mount it)

Engine is a Thunder Tiger Pro .61 Prop is APC 11-7P. Flys my 8.5 lb high wing "spy plane" well, not fast but well. I suggest you try an 11-6P or -7P. If you want speed go up in pitch, thrust go down in pitch. Cliff