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January 05, 2004
OK Gingerino...here we go....
The amount of choke (in terms of manual
cable/jet travel) that is required to...
1. get the engine to "fire" to begin with
2. allow it to continue running smoothly
(decreasing amount) as it warms up to
normal operating temperature.
Fr'instance:
On 40-45F+ mornings, no choke is really
needed at all. A couple of turns of the
motor with the starter button is all it takes.
We let the oil pressure come up and fast
idle it for a minute or so (1200-1500rpm)
using our right foot, then drive it gently
'til it comes up to normal operating temp.
It it runs a little roughly when we first
move off, we use the minimum amount
of choke required to get it to run smoothly
until it will do so with no choke at all....
which should happen fairly quickly.
On 30F mornings, we pull the choke fully
out before engaging the starter. A healthy
and well tuned engine will fire immediately and we immediately reduce
choke to the min. req'd for initial warm-up,
(again...engine running smoothly)
which if the "fast idle" screw is properly
adjusted, won't be over 1500rpm.
We let it warm up for maybe two minutes,
then proceed as before.
You want a rich mix for initial start but as
soon as it fires, the min. required so as
to prevent cylinder "bore washing" due to
too rich a mixture which results in raw, unburnt fuel traveling down the
bores,
diluting lubricating oil. This is bad.
You also want to turn the engine over
several times in really cold weather after
an overnight "sit", to get some oil moving through the system before
initiating a start.
They say that 50% of normal wear and tear on cylinder bores is caused by
insufficient lubrication on initial start (before the oil pressure comes
up and
the oil warms for "splash" effect...cold
oil doesn't "splash".....very well, anyway).
The BE has a starter "pull" (I have a
button) separate from the ignition switch.
So in really cold weather after an overnight sit, I turn the engine over
about
5 times with the starter before "switching
on"....get a little oil moving around in there before introducing spark.
I do this
with the electric fuel pump in the off
position. Once the engine fires, the fuel
pump switch is energized. So we get
a rich mixture for initial start but there's
no pressure "forcing" more fuel in then is
absolutely necessary for initial start.
Cap'n. Bob
'60 :{)
PilotRob@... 28024
Posted on January 5, 2004 05:27 PM
Posted to category(s) Carburetor | Electrical System | Engine (external) | Engine (internal) | Fuel System | Gauges | Ignition System | Interior | Lubrication System | Specifications | Technical Info | Tuning
