MTFCA Forum

Is the inlet thread on a Holley NH carburetor 1/8 NPT ?
Tried running a new brass fitting and it would not start.
Chased the threads with a die with no help.
Threads in carburetor visually appear to be in good shape.
Curious before I pull the carburetor off an run a tap in which is
going to result in pulling apart and cleaning out possible chips and trash.

Yes, 1/8 NPT on inlet elbow. Tapping with carb mounted on intake provides poor working spaces, so care in going in straight. Use of vacuum could help remove minor iron chips in tapping. IMO, remove the carb and do bench work.

Also, if you have the 1/8 NPT die, use it to check the threads on the elbow.

Roger

Your new fitting is suspect. Dont ruin a carb body modifying it to fit the bad fitting that needs a correct thread cutting.

thank you all.
Pulled the carburetor an found a burr on the face of the thread inlet.
Ran a tap in and cleaned up the threads.
Fitting went in perfectly.