Hi Scot,
The relationship between the mixture enrichment caused by pulling the
choke, and the normal running mixture is not really adjustable.
IMHO the important things are to ensure that the idle mixture is set
correctly when the engine is at normal operating temperature and that
the engine idle speed is set using the slow running valves, once that is
done most BJ8s will start from cold with about 1/2 choke unless the
temperature is really low, like below freezing.
On BJ8s it is very common to find that the idle speed has been adjusted
using the fast idle screws rather than the slow running valves. This is
usually necessitated by some other factor such as incorrect timing, or
incorrect mixture adjustment which prevents the engine from idling even
with the slow running valves wide open.
The result of using the fast idle screw to set the idle is that the
throttle starts to open as soon as one starts to apply the choke and
then the engine is reving way too high before the mixture enrichment
begins.
So here is the procedure I use, the whole carburetor adjustment
procedure takes about 2 minutes.
With the ignition system set up correctly.
1. Get the engine hot and adjust the jet adjusting screws to get the
fastest idle; which you can check by lifting the piston.
2. Ensure that the tips of the fast idle screws are about 1 turn off the
stop on the throttle shaft.
3. Adjust the idle using the slow running valve.
Michael Salter
www.precisionsportscar.com
-----Original Message-----
From: owner-healeys@autox.team.net [mailto:owner-healeys@autox.team.net]
On Behalf Of Scot paulson
Sent: Wednesday, June 16, 2004 5:56 PM
To: Dave & Marlene; list
Subject: Re: Re timing marks
Message text written by Dave & Marlene
>My experience is that on a completely cold engine, (overnight) if it
will start without a choke, the mixture is a bit too rich. Maybe the jet
adjusting nuts could be leaned a bit or the choke linkage isn't
completely releasing. (Jets not returning to their full up position
when the cable is released.) Not a serious problem as long as you are
happy with the way it runs.
Dave Russell
BN2<
Dave,
Along these same lines,my BJ8 will not start without choke, however, I
do
not think it is adjusted correctly and am not happy with the idle as the
engine warms up.
Frankly, this basic adjustment is somewhat of a mystery to me and I do
not
know how to correctly adjust my choke. I am familiar with the slow idle
and
jet adjusting screws.
Could you or someone on the list be instructive concerning choke
calibration?
Currently, when I have full choke applied on a cold engine it coughs and
sputters barely maintaining 1000 RPM with noticeable black smoke out the
back! This transitions to a nice idle and no smoke as the engine warms.
Any tips greatly appreciated.
Scot
'66 BJ8
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