Mailing List flyrotary@lancaironline.net Message #49159
From: Steve Brooks <cozy4pilot@gmail.com>
Subject: Re: [FlyRotary] No start
Date: Sat, 21 Nov 2009 12:20:37 -0500
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
You may be onto something.  I measured the voltage while cranking, and the drop didn't seem to be bad, but if the EC-2 or the ignition coils are on the edge voltage wise, that may be enough to cause the issue.  I am using an Odyssey  PC680 battery, and in fact, I bought a new one, and installed it last night thinking that perhaps there was an issue with the battery.  The one I replaced was about three years old.  Same issue on the new battery though.

Bobby Hughes suggested that I power the coils, injectors, etc, along with the EC-2 on the spare test battery.  I am going to try that after lunch, so if that works, it very well be a voltage issue.

Steve

Lynn Hanover wrote:
Steve,

I removed the battery cable running to the starter, and using a spare
battery, and a jumper cable for the ground, I cranked the starter with
this battery, which was isolated from the airplanes electrical system.
It had good spark on both rotors .... yeah !!!

It still sounds like low battery voltage during cranking.
 
There is a minimum voltage below which some components will no longer function. A volt meter on the battery during cranking would give you the actual voltage available to run the electronics. Starters can draw over 100 amps during cranking. Quite a load for a small battery. The race car will start about 4 times on the little garden tractor battery. Then nothing. So we start up with a big group 24 paste battery with an aircraft style plug in cable made of welding wires. That jump battery is in parallel with the tractor battery as well so we charge the racer and the jump battery by leavng the tractor running.
 
Lynn E. Hanover

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