AirTech

My Feedback: (18)

Rainman,

I finally figured out the problem with the 40RV. I forgot to mention that I was running a brand new PCM receiver and a JR 9303 transmitter on that airplane. The fact of the matter was that the throttle servo was not only reversed, also the throws end points were way off. I don't know if you are aware or not, when you remove the mechanical stop for the idle adjustment of the throttle butterfly the butterfly will be able to rotate a full 180 degrees. So in my case the throttle was closing on the opposite side of normal, and in the RCS website http://www.rcshowcase.com/html/faq.html FAQ section it's very clearly stated "The throttle shaft OPENS the throttle butterfly by turning CCW (while looking down at the shaft)."

After I got that mess straighten out I could prime it 10 to 15 revolutions, choke on, ignition on, and it will fire on the third or fourth flip. Then choke off, two more flips and it will start right away. Idles at 1900 to 2000 RPM's and turns a 20-10 BME prop at 6200.

I will suggest several things in your particular case. First, disconnect the throttle servo and move the throttle arm all the way forward (shaft will move CW) until it stops, at this point the throttle is fully closed. Mark with a felt tip that location in relation to the shaft c-clip. At this time set your throttle stick to full idle and your trim should be set to the full shutdown position. Make sure your radio end point trim adjustment is set to 50% of the total travel (i.e. total travel 150%/2=75% for the JR9303), this depends on the type of radio you are using.

Now move the throttle shaft CCW approximately 90 degrees. This should be your fully open position. Mark that spot with a felt tip pen for future reference. Connect your servo arm back up and make sure that it matches close to your first mark. If not make a mechanical adjustment of the linkage until it does. After that move the servo with the transmitter all the way to full throttle and adjust the high endpoint by the radio trim until it does.

Now with the throttle fully opened and the choke engaged prime it 10 to 20 flips (don’t worry it wont flood). Take your throttle to idle, make sure the trim is set to fast idle and turn the ignition switch on. Flip it until it fires and after it does remove the choke and flip it again, it should start. Set your idle and full throtle RPM's with the help of a tachometer to fine tune the end points.

If you are still having problems, try closing the choke and covering the intake with a finger while priming it at least 20 flips (a helping hand come handy at this time). Try the same starting sequence and if it fires and then it dies (while at fast idle) you must have a bad carburetor pump. If it doesn’t fire at all, then you have a defective ignition, a bad wire, or plug, or your Hall sensor timing position is not good. (See the “How is the ignition Sensor adjusted on a ZDZ® engine? Section on the FAQ section of the RCS website.

Please let me know if this helps you at all because I am trying to compile information to help others in resolving problems with these amazing little gas engines. Good luck and happy flying.