ZDZ 100 NG problems
I have a fairly new ZDZ 100 ng on an Aviation Models 35% Yak. I can't seem to get much power out of the engine; it just flies the plane/ no great power. The engine only produces aprox 6,000 rpm with a 26/10 bambula. Numerous attempts have been made to tune it with more rpms to no avail. One time it ran 6150 rpms, but was too lean. It seems to be running cool enough with the cowl on( 220 degrees or less). Oil is synthetic at 40:1 mixture. Exhaust system is JMB cannisters with headers. I am going to try putting the stock mufflers back on and checking the performance. This engine was sent to you around 3-4 weeks ago with a noise. The technician stated that everything was ok and ran it on the test stand with a 26/10 prop at 6400 rpms. He also indicated that the noise was the wrist pin bearing and would not be a problem. I need to get more power out of this engine to fly my 30 pound airplane. Also, when rich enough, the engine will start ok/transition ok. When the engine is lean, it will be difficult to start. The needles seem to adjust the mixture without problem. I did not adjust the timing since coming back from your shop. I assumed that the technician had adjusted it and was happy with its' setting. This is not a black head or blue head, just gray. I either need some adjustment or a more powerful engine.
Ron