Bobs
05-09-2007, 10:28 PM
Just finished building a Spectra G with 231 Zenoah (TRM). The instructions said to set both carb needles at one and a half turns open and to never go lower than one and three-eighths turns open. Anyway, at one and a half turns the motor will not spool up enough to even lift off. When I checked the spark plug it was wet. What carb settings are more realistic? I have a Bergen with a 260 Zenoah and for starters I set my throttle curve up the same way (10 27 29 30 32 36 100); however, even at half throttle the RPMs are not high enough to lift off. I tried richening up the low speed needle per the instructions but that made it worse. I then leaned it up a little bit and that did raise the head speed but then the real problem surfaced: as the blades spun up faster a rattling sound developed and became very noticeable. Any ideas as to what that rattling noise is? It sounds like it's in the gearing. The build went very well. The only thing I can think of is that the directions mentioned a shim (gasket) that goes between the tail gear case and the tail boom and there was no shim/gasket included in the kit. Also, this has the new closed gear case and it does not appear to use a shim. A friend also has a Spectra G kit yet to be built and he checked his kit and his did not have the shim/gasket either. Anyway, that's all I can think of that could be wrong. The instructions were very straight forward and easy to follow so I can't think of what could be wrong to make that noise. Any ideas greatly appreciated. BTW, went through over a tank of fuel and still have not left the ground. Also, the engine temps (read right next to the spark plug using a laser) never went above 140 degrees. The 260 in my Bergen reads 230 degrees at that same location, next to the spark plug.