My evolution engine for alpha trainer usuall starts on the first flip. The trouble is that 90 percent of the times, it is running backwards. Why would this be?

It's not uncommon with those engines when new. Sometimes it's due to over-priming, sometimes it's a combination of a too-hot glowplug or too much nitro in the fuel.

Basically, the engine is just fireing a tad early as you flip it up on compression, so it turns around and goes the other way. Sometimes just flipping harder "fixes" the problem.

You can also just flip it backwards and the engine will run forwards.

Kirk,
don't you have something to program?[8D]

As Kirk said, it is not uncommon for engines to run backwards when new. What is probably happening when you start it is you hit the compression stroke and it kicks backward and runs the wrong way. If you are using a chicken stick to start, be sure to follow through on your flip to get it going the right direction.

Chris,

Im in a testing cycle right now. "start program, wait for something to break, fix it, start again". Lots and lots of waiting around for something to go wrong.

You could also use an electric starter to keep from having the back compression stroke. Just a thought. On another note, are you sure engine is running backwards, and that the prop isn't on backwards instead? I have an evolution trainer system on my Extra Easy 2, with the 3 blade prop. Make sure the "E" on the prop is facing outward, you would be surprised how easy it is to make that mistake.

If you mount a prop backwards it still pushes air the same way. It just doesn't do it quite as well. Try it and see, you won't hurt anything. It's actually an old trick used with throttleless engines to reduce the thrust.

in most cases, if it starts backwards, jsut open op the throttle to full, and it will kick back 'round. usually they don't run very well backward, and they will only run in a slim throttle range.