Reply To: Resizing UU-2 main jets

[Edgar Minnie]

Mark, I’m not sure off the top of my head which size jets and venturies are correct. You definitely want to be in the rich side. I use a five gas analyzer to tune the carb after setting it up. With E10 pump gas you definitely need to add more fuel than stock. Since Pierce was one of the largest CID motors to use the UUR2 most swapped out carbs are undersized as far as the internal components go. I loaned out my Stromberg catalog with all the part numbers and specifications and it didn’t get returned so I can’t look up the numbers for you. You can use the old fashion method of reading spark plugs, but fuel today doesn’t tend to leave much sign of the burn on the electrodes. If your running an electric fuel pump, be sure to keep the pressure on the low side to prevent fires from over pumping, also, too much fuel pressure will cause the car to run too rich.Without starting from a factory stock carb, getting everything right can be very challenging. If the large and small venturies are correct, jetting it is fairly straight forward. If thr carb is way undersized then getting it to perform correctly overall is very difficult. Your best bet would to contact someone with another model 43 and see what they have in their carb. Ed