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Old Skool_R’s How To: BENCH SYNCHRONZING YOUR CARBURETORS
Tools needed:
1 long zip tie
Phillips screwdriver
Vernier calipers
So after your carbs are all cleaned up, you should bench sync the carbs
to get them close. It’s recommended the carbs should be synched with
a professional sync tool after you get the carbs on and bike running.
Note: I have bench synced my own carbs using the method below and
then synced them with a mercury manometer and they were VERY
VERY close. All cylinders were on except for one that needed a very
small adjustment. So if you’re cheap like me, and don’t want to buy
the sync tool, this method should work fine.
First thing to do is zip-tie the throttle lever open all the way. You can
look in the picture to see where I ran the tie. I believe this is the best
way. After you have the zip tie on, manually try to open the throttle
more, if its open all the way it won’t move any more, if you can still
move it, you need to tighten the zip tie more.
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Starting with the carburetor that has the throttle stop (see pics) you
will need to measure from the bottom of the throttle blade to the
lowest part of the throttle bore. Right before you get the caliper all the
way to the bottom of the bore, rock it back and forth a small amount.
You will feel it drag, then get loose, then drag again. When it loosens
up, you are close to the lowest part of the bore. Roll the micrometer
down until it hits the low spot then record your measurement, then
move to carb #2 and adjust it to your first measurement. Then 3. Then
4. Measure and adjust in order 1-4 (see pics)
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Measure this carb first, it is the base setting for the rest of the carbs.
Red circles show adjusting screws.
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Example: You can see in the last pic the base carb measurement was
0.664. So now when i measure carb #2, if the measurement is 0.667 I
can turn the adjusting screw between carbs #1 and #2 until the
measurement for carb #2 is 0.664, the same as carb #1. Do the same
for carbs 3 and 4, then you’re all done. Easy right?
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