Interference
#51

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From: Hammond, IN
i'm pretty much sure it was the wind...it was windy this last saturday too and when i went to make a turn, sometimes the wind would keep pushing the lower wing tip down. make sence?
#52

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From: Whitestone,
NY
Tired Old Man - I don't know if this is an interference problem - this has to do with a lack of spark on a Zenoah 26 with magneto, Champion R27C plug. Bought this used on a Kangke Monocoupe one month ago. Tested the engine and it worked like a top (cranked the engine with my starter). In the past few weeks I've done some work upgrading the plane - I'm still on 72Mhz - replaced the non-pcm receiver for a Futaba R149 DP \ Dual Conversion, PCM. The cowl on this plane is in two parts, and the inner-section can rub against the ignition wires. While working on the plane I noticed one of the ignition wires looked frayed where it was pinched-into it's lead, so I taped that over. Tried staring the engine this morning - no spark. I tried to fix the frayed-wire connection and also re-pinched the ground connection, but still no spark. I read that you might need to get some velocity into the prop flip to build the charge for the spark, so I used the starter - no spark. Would you have any suggestions? I'm assuming that you can see the spark with the plug not seated in the engine but connected to it's lead wire, right? Thanks for any ideas.
Mike
Mike
#53

The spark is often difficult to see. I've done the spark check at night turning most of the lights off in a room. You want to see a bluish spark but it isn't a large spark. This is why ease of starting and better idle is obtained from an electronic ignition as it produces a stronger spark, especially at low rpms.
#54

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From: Whitestone,
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AA5BY - Got it fixed. Turns out I was not spinning the prop fast enough. Read here on RCU that, for a magneto engine, you need to spin anywhere from 2-600 RPM to generate a spark - didn't know that before (my first magneto). Also that you have to ground the plug against the engine (I don't need to do that for my EI plugs). So, using my starter and grounding the plug I have SPARK!! Very cool to see that spark after looking everything over 10 times. Evidently I did fix the wiring problem. After putting it together I cranked the engine - choke closed - and got a pop! Will test fully this weekend.



