I need some help with my new broken in FL70. I broke the engine in following the instructions perfectly. In fact I am up to 4 tanks of fuel and today was going to be the first real flight. Untill today I had no problems at all and had even decided that I just loved the enigine. BUT today I could not get the engine to run past idle. It would run at idle but if I brought the throttle up at all it would backfire and stop. No matter what I set the main needle valve it would backfire I tried for over two hours... it would just backfire ALLOT and stop. So I packed it up for the day.

It has run perfectly until now again it only has 4 tanks through it and have been very careful! I have to wonder if this engine is any good? Can it be repaired? Do the valves need to be adjusted already?

Any help would be great!!!!

Thanks!

Open the high-speed needle valve about 1/2 turn from wherever it is right now, and then work on starting the engine at 1/4 to 1/3 throttle. You should be able to get the engine to start and accelerate to full (keep the battery on the glow plug). You can then reset the engine.

Very likely, the idle mixture's too rich, which is causing the backfiring when you try to open the throttle. Get the engine started at a higher throttle setting and go from there and reset the engine. As the weather changes from day-to-day, you'll find that the carb settings will change a bit as well.