At 12:42 PM 12/16/99 EST, RC1NUKE@aol.com wrote:
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>Just started the car yesterday.
Yay!
>I can't seem to get the idle right and I know the PO was wanking with the
>adjustments.
Boo! Sounds as if its your turn to do some 'wanking'... :)
>Does anyone know the bench settings for the CO coarse and fine adjusts and
>the bypass adjust. I rebuilt the carb but the instructions didn't talk about
>the base settings. The engine is just rebuilt. 77 spit CA style.
Ok first make sure your timing is set properly is not erratic.No vacumm
leaks? Good. Since the engine runs, check the plugs, they should be in a
uniform condition (all the same); if not, you may have a vacuum leak/sticky
piston ring/valve etc. (common on a new rebuild) Do a compression test to
verify.
Now on to the carb adjustments. Does it have the dreaded water choke (as
required by CA authorities)? You _must_ be sure the choke is fully
disengaged before attempting to adjust the warm running mixture.
You are perceptive enough to realize that the bypass/decel valve could
affect the mixture. Did you mess with its adjustment during rebuild? If
so, tsk tsk. Better for now to make a blanking gasket to get it out of
consideration. You can attempt to set it after the idle is better.
If you have all those prerequisites covered, you may now evaluate the idle
mixture by looking at the condition of the sparkplugs. Proper condition is
for the electrodes to be clean with a light-brown coating. Sooty/black
means you are running too rich, white means too lean.
Set the fine idle mixture screw (front side of carb, near the bypass valve)
to an initial point, by screwing it clockwise till it _lightly_ bottoms,
then CCW one turn. Then use the proper mixture adjusting tool through the
dashpot opening, so that you don't damage your new air piston diaphragm,
and turn it clockwise to richen and CCW to lean. (BTW you should have the
air cleaner installed during this setup.)
The effective range of the coarse adjustment is about five turns from its
full rich (CW) setting. Too far in the CCW direction and the needle threads
may back out and you will have to reach under the air piston and hold the
needle base up to re-engage it.
A common starting point for the needle is to have its threaded holder flush
with the bottom of the air piston. But, that is just a starting point.
Try that stuff then get back to us if you still can't get it right. Then we
will check the bypass valve if neccessary.
Regards,
Atwell Haines
'79 Spitfire
Succasunna, NJ USA
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