S
sunofjustice
Guest
Always wanted to do a dual carb bike engine............ ever since I got my first engine from kingsmotorbikes. Addind dual carbs to an engine is an old hotrodder trick to achieve volumatic efficiency with a v-8 automotive engine. A v-8 can run reasonable well with a 2bbl......... a four bbl........or even a 6bbl (tri-power) ............but, th' engine has EIGHT cylinders. Some where along th' intake side some cylinders lean out or run rich. In th' case of our china-fire injuns.......its intake side is really being CHOKED off (or restricted)................... which is a FUEL ECONOMY trick to get mileage and probably to keep th' revs down. All th' restrictions is creating TORQUE....................thusly, causing VIBRATION!!!!!! A boost bootle can "cover up" th' fact your engine is STILL restricted .............but a bigger intake........bigger carb............will show bigger gains but, at a bigger cost. This is th' reasoning that influenced my ultimate vision of my "blue oni" (70cc mtb). I intended to run just a single carb to get th' bike functional.............after break-in..........THEN install th' second carb! This build I wanted to imply HIGH concepts.......LOW dollars. Th' stock carb is 12mm( i think).......th' stock cyl head is roughly 20mm already............add TWO 12mm carbs.......you get 24mm! Should work just like a 4bbl.......use one carb for low speed/ cruising ( primaries) , second carb .........high speed/ power-blasts (secondaries). The only crux of th' matter was th' intake manifold .................which I just recently solved.........use a pocket bike DUAL EXHAUST!!! Cut off what you need.......NO WELDING. CHEAP. CHEAP. CHEAP. Besides, I got a bunch of extra carbs and manifolds left over from failed happy times ........why not recycle?