Originally Posted by
jpalessi
Brandon,
the problem with not touching the MRN is that like you said "leave it at factory at 2 oclock" well every new engine I've seen the factory setting is different. when the carbs are manufactured they use a "power tap" to thread the carbs and the stating point is always different, so each carb is different. I usually set mine at 3-1/4 turn from bottomed (11o'clock), and it's within a couple hours of tuned. dont be afraid of the MRN, it really helps get them dialed in perfect if you understand how it works with the LSN.
Not saying you were wrong, I understand how needles work. No offense to the guy asking the question, but someone who has to ask why an engine doesn't idle down, doesn't need to be messing with a MRN. There's no reason with the factory setting that an OS carb won't achieve good idle. That's all. I ran plenty of VSpecs in my day and all of them came to idle just fine with factory settings on the mid range.
It would be like a doctor telling someone to go get a medicine decribed by all the scientific names of the ingredients, instead of saying, "go get tylenol".