Not sure if this was unique to my coupe; but learned this from the article on
carbs in Coup Capers:
Close the throttle all the way
Then prime (mine takes 1 or 2 shots depending on temperature and how
full first shot was)
Then open throttle about 3/4 to an inch and start
With this technique I can't remember it ever taking more that 2
revolutions to start.
Before learning this technique I had always primed it with throttle
open and it often took several
revolutions to start.
Dan C
On Jun 17, 2010, at 11:26 PM, Gordon Smith wrote:
> If you have trouble starting your Coupe in California with a new battery and
> have problems starting, I would check the grounding very well. There is
> nothing any worse than a cough and backfire through the carb, and not have
> enough battery to keep the engine turning and suck it up into the engine. I
> have seen too many people over prime, and have the engine flood and backfire.
> A good strong battery may alow you to keep that engine turning and start
> quickly, in that situation.
>
>
> Socialism will eventually run out of other peoples money.
>
> --- On Thu, 6/17/10, Daniel Arditi <[email protected]> wrote:
>
> From: Daniel Arditi <[email protected]>
> Subject: [ercoupe-tech] Battery capacity for cold starts
> To: [email protected], [email protected]
> Date: Thursday, June 17, 2010, 8:35 PM
>
>
>
> Linda,
>
> There is one parameter given by the battery manufacturer that
> helps us to understand how a battery will behave at cold temperatures at the
> moment of an engine start (cranking). That parameter is called CCA (Cold
> Cranking Amps) and is defined as the number of amperes a battery can support
> for 30 seconds at a temperature of 0°F until the battery voltage drops to
> 1.20 volts per cell, or 7.20 volts for a 12V battery. Thus, a 12V battery
> that carries a rating of 600 CCA tells us that the battery will provide 600
> amperes for 30 seconds at 0°F before the voltage falls to 7.20V.
>
> Well, perhaps a bit technical, but the concept is that the more CCA the more
> 'ability' the battery has to perform at low temperatures during cranking.
>
> For the Concorde batteries:
>
> RG-25 CCA = 225 Amps.
>
> CB-25 CCA = 235 Amps.
>
> RG-35A CCA= 390 Amps.
>
> Comparing the numbers above, you will see for example that an RG-35A battery
> will perform better at the moment of an engine start than the xx-25 ones at
> very low temperatures (but xx-35 family batteries are not intended for
> Ercoupe use, as far as I know).
>
> Another thing (from Concorde's manual):
>
> Capacity Loss Due to Low Temperatures
>
> Operating a storage battery in cold weather is equivalent to using a battery
> of lower
>
> capacity. For example, a fully charged battery at 80º F may be capable of
> starting an
>
> engine twenty times. At 0º F the same battery may start the engine only three
> times.
>
> Low temperature greatly increases the time necessary for charging a battery.
> A battery
>
> which could be recharged in an hour at 80º F while flying may require
> approximately five hours for charging when the temperature is 0º F During
> cold weather, keep batteries fully charged. Make every effort to conserve
> battery power.
>
>
> Hope this information helps.
>
> Daniel Arditi
> Ercoupe Argentina Group.
> Buenos Aires.
>
>
> From: Linda Abrams <[email protected]>
> To: [email protected]
> Sent: Thu, June 17, 2010 8:09:08 PM
> Subject: [ercoupe-tech] batteries
>
>
> What John wrote below helps a lot to understand the relationship of
> battery & generator. The problem I've had recently has not related
> to running enough electrical items in flight, rather, it has been
> battery capacity for cold starts: e.g. when my local A&P ran a bunch
> of "test starts," such as when he was adjusting the pull-starter he
> tried it out a bunch of times, or when he cleaned the spark plugs and
> was testing whether that smoothed-out how the engine was running.
> Then when I went to fly next, there was not enough power to start
> up. Yesterday, he had to give it a "jump start," but after I flew
> 45 min. to my destination, did 3-4 starts & run-ups there for the
> prop-balancing guy, and then it sat for 2-3 hrs. but still started
> fine for me to fly home.
>
> John (et al.), can you please address battery capacity for cold
> starts? Is it correct that a Concorde 35 will be better for this
> purpose than a 25? The A&P wants me to get a 35 (and, Hartmut: he
> says a field approval is no problem, and he'll measure the box for
> fit, before buying it.) Is a 35 better for my purposes than a 25?
> Other than the few lbs. extra weight, am I asking for any kind of
> additional problems if I get the 35? My 414-C has a C-85 and a
> generator, not an alternator.
>
> Linda
> N3437H (Sky Sprite)
> L.A.
>
> 1a. Re: batteries
> Posted by: "John Cooper" [email protected]
> Date: Wed Jun 16, 2010 6:16 am ((PDT))
>
> On 6/14/2010 7:31 PM, Todd Fischer wrote:
>
> > Reading the Univair memo it sounded like the older generators just
> > couldn't handle charging the larger batteries and only approved the
> > RG25 batteries.
> >
> >
> This is a misconception. The larger battery has more capacity, so it
> will take longer to discharge, as well as longer to recharge, but,
> unless you continually discharge it, which means your constant
> electrical load exceeds the generator capacity, it will remain charged
> the same as a smaller battery. OTOH, if you are exceeding the capacity
> of the generator on a regular basis, the smaller battery will go flat
> faster.
>
> If the RG-35 battery is in good shape, and you charge it up (once), and
> you do not exceed the capacity of the generator with your electrical
> load, then the battery will work fine.
>
> As an aside, the constant load on the electrical system should not
> exceed 80% of the generator capacity. Constant load includes comm
> recievers, nav radios, transponders, nav lights, etc.; everything that
> is not intermittent, e.g. landing lights, flap motors, gear motors, comm
> transmitters, etc.
>
> -- John Cooper
> Skyport East
> www.skyportservices.net
>
>
>
>
>
>
