flyrotary@lancaironline.net Mailing List Archive

Bill, my experience is that at idle, you are running only on the primary injectors, if you turn off the secondary there is absolutely no effect at all (provided you are below the staging point) - because they are not injecting. However, if you have power to both primary and secondary injectors and turnoff the primary injectors - the secondary injectors will kick in (or should) and start injecting.

But, what I have found is that if I don’t' immedately turn the mixture control to full rich immediately after turning off the primary injectors - the engine will die. If in immedately enrich the engine will cough and then start to run at which point I must lean it back and then the engine will idle fine on the secondary injectors. My theory is there is no fuel flowing in the secondary runners because the secondary injectors are not firing - so for an instance there is nothing but air flowing into the combustion chamber which can cause it to die, unless you quickly over enrich it. (but the theory could be all wet {:>)

From: Bill Bradburry

Sent: Wednesday, January 12, 2011 9:45 PM

To: Rotary motors in aircraft

Subject: [FlyRotary] Apex seals and MAP table corruption?

Chris, what is the latest scoop on the stuck apex seals? Did they free up?

I currently have every thing (cowl, inspections plates, etc.) opened up so I can’t investigate this further right now, but the last time I taxied my plane, I noticed that it was really lean at idle (took mixture knob to 4 pm) and when I ran it up, I could only get a little over 6K (previous would go to 6900!) rpm and the mixture knob full rich would not bring the mixture bar graph visible. I am pretty certain that my MAP table is corrupted. This is the first time this has happened to me.

I am pretty certain that it was the time before that I switched the CPU from “A” to “B” and tested my coils. This was the first time I had done this. I normally just run it in “A” and am trying to get the tuning in so I can copy that to “B”.

Also, when I test the injectors…I have only done this at idle, if I disable the secondary, it stumbles, but keeps running. When I disable the primary, it would die if I didn’t immediately switch it back. Sounds like the cold start might not be engaging on the primary??? Does anybody have any suggestions?

Those of you who have had your MAP table corrupted, was a switch between CPUs and or coil testing involved prior to the problem? Could there be some involvement here???

Bill B