Calculations and useful numbers:
Calculate CC: Bore X Bore X Stroke X 0.0031416
To set up a 009 or 050 distributor when using a degreed pulley wheel, make a mark on the 32 degrees before TDC with a felt pen or liquid paper, then run the engine using a strobe light attached, slowly raising the revs, then when the engine is at full advance (you will know when that is as the mark you made stops moving) turn the distributor to move the mark until it lines up with the case centre.
To balance a set of dual carbs is not all that difficult, if you have a
carb synchronizer this can be used to measure rather than listening for
evenness. Either way, firstly disconnect the linkage to both of the carbs, then
screw in both idle adjustment screws in about two turns. If you are going to use
a synchronizer, remove the air filters. Now start the engine, it should run
relatively high, now by adjusting only one idle screw up and then down until the
engine sounds sweet and smooth or measures the same on both sides. Turn off the
engine. Reconnect the linkage to both carbs and loosen the adjustments on one
side. Now adjust the linkage on that side until both throttle arms rest on their
stops. Open the throttle from the cable link (centre of the cross-bar) noting
which carb opens first, adjust the linkage to raise or lower that throttle rest
and continue until both carbs open together, then tighten the linkage lock nuts
and re- fit the air filters. Re-start the engine and unwind the idle screws
evenly until you have a nice running engine.
Thanks for reading. I hope it has been useful.
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