In a message dated 3/24/2008 4:52:19 PM Pacific Daylight Time,
gtpjimgammon@yahoo.com writes:
Hi
I looked, but didn't find.
Could someone please send a link to the procedure on setting up SU carbs on
a 2000?
I just can't recall how, though it has only been 30 years since the last
time I did it....
I have the idle setting on each carb, and an air flow meter, but I can't
recall how to do the higher speed mixture setting.
JimG 1969 2k
Jim,
Check the 311s.org wiki tech section. My "still not quite done" carb
tuning link is there now.
The quick rundown is:
Set the idle airflow balance with the idle speed screws found down by the
throttle shafts.
Using the service screw raise the engine speed to 2000 rpm. Set the high
speed airflow balance with the screw on the bar connecting the two carbs. Lower
the speed to idle and double check the idle balance.
Using the service screw again raise the engine speed back to 2000 rpm.
Adjust the mixture knobs to achieve maximum rpm. If it starts to get too high
back
off the service screw to 2000 rpm. To check the mixture: if you raise the
slide a little and the engine speeds up, that carb is rich and the mixture knob
needs to be turned in raising the nozzle. With a little practice you can push
the slide down a little. If the engine speeds up that carb is lean and the
mixture knob needs to be turned out lowering the nozzle. At the correct
setting lowering or raising the slide will slow the engine.
Lower the engine speed back to idle by backing out the service screw. At
this point you are likely to need to readjust the idle speed. Do this with the
idle speed screws making sure to verify that the air flow remains balanced.
The idle mixture can be checked using the slide raise and lower trick. It
should be correct. If it's not too far off call it good. If it's way rich you
could have worn needles and nozzles. If it's rich or lean enough that you want
to do something about it the needle can be slid out a few thousanths of an
inch to lean or in a few to richen. This also effects the high speed mixture
but not very much. The promary effect is at idle.
Once you get to this point it is time to road test. If you get stumbles at
cruise you are a little lean, riched by about 1/4 turn. Check the plugs, if
carboned lean by about 1/4 turn. A couple tries and it should be dialed in.
If you stumble when you floor it the dash pot oil is low or too thin.
Normally use about a 10w oil, atf works fine. If that isn't thick enough
motorcycle
fork oil works and is available in lots of weights. Once you get up to 20w
or higher single weight engine oil works.
That should cover most of the points. Let me know if you have any questions.
keith "the slow carb guy" williams
**************Create a Home Theater Like the Pros. Watch the video on AOL
Home.
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