I have just recently bought my 240z. I bought your carb tune up video, which help a lot, and was able to rebuild my carbs. I used a cheep 20 dollar rebuild kit from autozone. This only had gaskets and fuel line. I decide not to use the needle/seat it came with because it broke while trying to install. I reused my old ones. I'm pretty sure this might be causing my richness problems but I was wounding if the N45 needle or nozzles could also cause my motor to run rich?

I'm most likely going to buy the needle/seat and SM needle from Ztherapy . Should I also replace the nozzles?

Reallity , check with Ztherapy. They wont tell you wrong. Just be vary shure that the choke linkage is not hanging up . The fuel line that runs form the float chamber to the adjustment on the carb is critical. If it is not plyable it will cause the choke to stick particially open. This will cause a vary rich mixture.

i'm in the middle of doing a rebuild of my 72 3 screw SU's and i found that my floats are off and is prob the reason for my car running rich. i would check your levels and your floats for leaks.... they will be heavy if so. You can check these while the carbs are on the car. i also found that i was using to much oil and that it was to heavy of weight. all of this makes the carbs run rich. so i hope that with all these things fixed i will have them on the car tomorrow and i have a uni-syn on the way.

After the rebuild it’s running a lot better. I still have a little backfiring during shifting. I think it’s from the lack of a dashpot. Besides that she is running great, except for the fact its a lot harder to start in the mornings ;-). Guess my next project is getting a choke cable. Thanks for the support all.