Bummer, I love the look of the duals, but if I want to race sounds like single carb is the way to go.
I've covered the basics but did get some additional ideas to check for. The carbs have no choke, there is no place to add a choke even. The 660's center squirters are pretty radical carbs. No power valves either. Tall bowl vents, got 'em. Brass floats with spring assist (good floats), rubber needle tip externally adjustable float level lowered BELOW specs. 7 lbs fuel pressure (gauge mounted on carb inlet).
However, ZERO clearance on linkage, "touch" them and they squirt HUGE quantities of fuel. I'll loosen the linkage, back off the accellerator pump shot and re-jet from 75 to 70's.
I have a hunch I'm treating the symptoms and will eventually have to go to single carb to do the SCCA thing.
How 'bout $35K down payment and I'll set you up on a "easy payment plan" for the rest?
