Ruxin carb think that’s the name

[UltraMaxPhazeX559]

Got an odd issue changed the J pipe a week after race to the loop pipe. Carb acts like it’s starving for fuel for 20 ft then takes off like crazy . I’ve bumped the jets both ways no change. I’ve cleaned the carb by hand and ultrasonic cleaner. Adjusted it changed plug changed coil and fuel pump. Changed valve cover with pulse changed lines and fuel filter. Has anyone actually seen these carbs wear out inside to the point you just can’t get them right. Valve lash is good head gaskets good motor idles 2,600 and purs. The issue is on starts and restarts. I’m baffled

 

[K12]

If it ran fine before the loop pipe, that's the problem.

 

[DD83]

I run the loop pipe and have had zero issues with it 2600 seems a little high for idle, have you tried changing your low speed jet. and, or cleaning it.

 

[95 shaw]

Says a lot about the effect the pipe has on the signal to the carb.

Loop pipes are generally much longer than a regular j pipe.

If the engine idles rich with the j pipe,(like most must) and smoothly with the loop, low speed jet will need to be larger, because of the change in signal at low rpm.

Nothing is plug and play.