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Setting Daytona Carbs


Setting Daytona Carbs

Developing a Baseline for Carb Tuning.

1) Warm up engine, shut down, check compression, replace plugs

2) Check points, set dwell (clean, reset, replace)

3) Check Timing & Distrib Curve Accuracy.

4) Remove Air Cleaner, insuring nothing falls into throats, (install adapter pipe for fuel return line),
thoroughly inspect for fuel leaks, check choke cable adjustment and operation
(including linkage & adjustments on carbs), check entire length of carb linkage for
inaccuracies or link binding, with quality flashlight inspect all carb throttle adj. screws for regularity.

5) Start engine and warm moderately, noticing running speed & condition, insure idle is 900-1000.

6) check air flow at each throat and mentally note, shut down, loosen all linkage jam nuts (with exception of rear carb),

7) Insure all carb throttle stops are touching on their respective set screw, insure choke stops allow throttles to assume full rest,
start engine again and recheck air flow, if necessary raise or lower to match while insuring idle speed remains at approx. 1000rpms.
once completed shut down engine.

8) Once all above steps checked and completed remove 1st plug and replace with 'Colortune Tool,' restart, turn mixture screw all the way in,
slowly unscrew until light (color) appears, continue backing out mixture screw until orange color appears, turn slowly in until 'Bunson Blue' color obtained (as noted earlier the high end of the blue scale seems to work out the best),
shut down and proceed to next cylinder.....repeat steps on all cylinders.

9) Idle may have raised at this point, recheck air intake volume again, reset as necessary for match and correct idle speed (850-900 rpms),
shut engine down, gently tighten jam nuts, insuring not to move throttles off their stops, tighten front linkage with return spring attached, .

10) With engine off fully depress throttle to insure free operation, restart engine and test engine acceleration and return to idle.

11) If engine accelerates and returns to idle properly, let idle, check all intake air volumes once more to insure no discrepancies, and color tune second time to insure constant firing by slightly turning mixture screw in & out while carefully scrutinizing color to insure best operation.

*The above takes into account that the carbs and other systems are in otherwise good operable condition and merely need adjusting.

*In the case of any cylinder or carb that doesn't have a nice stable range of adjustment the cleaning & adjusting of the internal components will be necessary.

*In the case of Carbs that fail to adjust properly, a host of problems can exist. If it's determined a carb cleaning/rebuild is in order, while the carbs are off
it is recommended that all intake Manifold O-rings are replaced, carb bases checked for flatness using a straightedge, all warped/deformed bases flattened by machining, carb bodies thoroughly cleaned and dried, all jets inspected, sized and noted, base gaskets replaced, needles & seats replaced, accelerator pump diaprams replaced, float levels carefully and accurately set, internal carb check balls checked for sticking, carbs reinstalled
and above Procedures repeated.

* When using a colortune it is best to try and check and adjust individual cylinders as quickly as possible, due to the lenght of time it takes to insure accuracy it might be neccesary to allow the engine to cool down occasionaly. However, haste makes waste and a methodical approach addressing anomolies as they are uncovered is a sound approach.
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