The Honda came out impressively...
The Honda came out impressively light for our rules. No melting lead, lead fumes, or welding on brackets-these are from A&A Manufacturing. Clamp-on lead weights are attached to the left door bars and around the left-front of the car.
I purchased 2 two-barrel to four-barrel adapters, bolted them back to back, and installed them under the carb. Instant plenum. Well, maybe there was a little benefit-it raised the rpm by about 1,000 before the problem occurred again. It looked like this engine might require a plenum somewhat bigger than my old 10-gallon hat. So I began to look elsewhere. I even changed back to a stock cam. No change in the extreme rich condition.
At this point, I was not looking for a cure but a fix. Surmising that the intake manifold was at fault, I looked for another way. First I drilled a 11/48-inch hole in the accelerator pump circuit. This would act as an air bleed into the float bowl. My thinking was the pump would overcome the air bleed and still get some squirt to the venturis. When this semi worked, I felt I was on the right track. However, the vacuum was still pulling fuel through the squirters at about 5,500 rpm.
I do not consider myself a carburetor man. After taking the carb off and apart for the 741st time, I removed the squirter. I turned the carb over and tapped it gently. Guess what? A pointed-end pin fell out of the hole under the squirter. This pin is part of a needle valve assembly. I suppose its weight would keep fuel from being sucked through the squirters under normal conditions. Nothing about this condition would be considered normal.
The 16x26-inch Howe two-core...
The 16x26-inch Howe two-core racing radiator nestles down in the front of the car. With this size radiator, only one of the Honda electric fans was used, saving some electrical drag.
First I tried putting a spring on top of the needle to help it stay closed. But there is only about 0.090 inch of room between the squirter bolt and the pin. So there would be no spring on the pin to fix this. Rooting around in the nether world of Sleepy's Workshop, I found a 0.155-inch-diameter steel ball that came from some bearing I cut apart long ago. I dropped this ball in place of the pin. Then I installed half of a ball-point pen spring atop the ball. Instant improvement.
Then the pump didn't want to overcome the spring. To make adjustments, I stacked gaskets under the squirter. The spring adjustment needs to be where the pump can barely overcome it.
I'm down to 54 jets with a 25 squirter. The power valve is still the 2.5 that Bob Oliver sent with the carb, but this may be changed in the tuning process at the track. When I look in the throat of the carb at 6,500 rpm, fuel seems to be coming from the right places in the correct amounts. We'll know more after we check the plugs at the track. It has been an interesting problem to fix.

The Honda engine responded...

The Honda engine responded best when the DUI distributor was advanced 43 degrees total. The Airmass Headers can be seen sandwiched in between the engine and the radiator.

The switches are mounted to...

The switches are mounted to the interior sheetmetal. The ignition switch activates a junction block. With the ignition switch on, the starter button is hot. The electric fan is also turned on with the ignition. This keeps me from forgetting to turn it on during a race. For safety, the electric fuel pump is activated by an engine oil pressure switch. No oil pressure, no fuel. When the carb is dry-you just changed jets-a momentary switch is used for a bypass to supply fuel.

Tony and Dalton team up on...

Tony and Dalton team up on setting valve lash. Just like a V-8, the Honda has 16 valves: 0.006-inch intake and 0.007-inch exhaust on the Colt cam.