i have had one since new. as far as the richness. get used to it. its the only way this engine runs . it runs best wide open. soon as you start backing off it will burble but wont quit. if you guys got this engine for 3d forget it. its more for pattern. i love the engine. i had one on a 160 greatplanes extra and it was very fast but not areobatic. it wont hover well with this engine. also you can not lean this engine to much. it will bite you on the ass quick. DEAD STICKS WILL ACCUR IF THIS ENGINE IS IS A NOTCH ON THE LEAN SIDE SO BE CAREFULL!!!!!! the best recomended set up for this engine is a 18/6 apc propeller.. os no.8 plug slimline pitts style muffler. is a little more expensive but worth it. and lastly 10% to 5% nitro. do not use 15%... and another thing dont crimp your exhoust stack on this muffler. thats ridiculous and does absulutly nothing. there are about 5 people in my club with this set up and no problem ever. remember keep it basic and simple and once you get it tuned leave it alone.... i hope this helps...... just my experience ...