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synchronizing 3carbs on kbl eng.

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flyrod
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synchronizing 3carbs on kbl eng.

Post by flyrod » Thu Dec 17, 2009 12:16 pm

Interested in learning how to tune 3 carb setup on herc. engine

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Al Benton
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Post by Al Benton » Thu Dec 17, 2009 1:18 pm

There's a good thread on KBL's at KBL RPM Problem There are others, do a Search using KBL as keyword for other discussions. THE RAZZ seems to have a good handle on making those carbs work together.

Al

THE RAZZ
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KB & KBL triple carb synchro with uni_sync tool

Post by THE RAZZ » Thu Dec 17, 2009 3:46 pm

Rod,
Buy this- http://www.1800vw.bizhosting.com/uni_sync.html $20

1) Remove all three carb flame arrestors.
2) Find the idle adjustment screw on each (3) carb.
3) Near the idle screw, find the screw that tightens the lever on the butterfly shaft.

Warm up the engine.
4) incease idle with the idle stop screw on the center (#2) carb +/- 700 RPM
5) Put the uni_sync on top of #2 carb.
6) Adjust the uni_sync center piece (screw R or L to open/close the port) until the ball is in the middle range marker.
7) When ball is about centered on carb #2, put it on carb #1.
8) Is the ball in the same place as #1?
If not, back off the butterfly lever screw and adjust butterfly #1 so the uni_sync ball is about in the same spot as #2.
9) tighen #1 lever screw.
10) Check #3 carb with uni_sync. If all three are close in the middle range marker your done. Check all buttlerfly screws for tighness.
Reset idle at +/-500 RPM. with the #2 carb idle stop screw. Then set #1 & #3 using #2 as the base

If #3 Carb is not the same. Adjust butterfly using step 8 (above)

Final check- Go back with uni_sync and check all carbs again noting if the are all close to the same spot of the uni_sync.
Note changing one can changes others. Fine tune repeating step 8 until all three are about at the same place on the uni_sync scale.

Reset idle to +/-500.
Check periodically for correct sync of carbs. There is a small balance tube between the 3 carbs but its possible to have one carb run lean if the (3) butterflys aren't sync'ed.

Getting familiar takes more time than the actual checking the sync. Once you've done it, it'll takes less than 5 min (while having a cafe Latte).
1942 17' barrelback 71923
1987 21' CC Stinger

flyrod
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carbs

Post by flyrod » Thu Dec 17, 2009 6:55 pm

Great info, thanks for takeing time.
sincerely, Jim

THE RAZZ
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Post by THE RAZZ » Fri Dec 18, 2009 12:48 pm

Jim,
Hope this helped.
Its a walk in the park the second time.
I suggest you check them at the beginning of the day. Thats probably overkill but its better safe than sorry.

On a related subject- does your setup have an adjustable or fixed main metering jet under the bowl?
1942 17' barrelback 71923
1987 21' CC Stinger

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