Rick,
I've never been a proponent of critical needle placement theory. Whatever the needle is flowing at any given snapshot in time is what is going through the spraybar at that same time. The volume in the fuel tubing doesn't change, so there is no delay in needle adjustment and mix ratio at the carb. Any "cleanout period" we think we hear is the result of the pipe cleaning itself out of excess fuel in the exhaust.
Place the needle where it is most convenient and allows for the best arrangement and access, then plumb accordingly. Don't be opposed to punching a hole in the side of the tub to gain access to the adjustment screw if you have to.
I've also been known to graft an OS needle socket into the spraybar of the carb. I also make a needle/boom block combination that works well in my BlackJack kits, but I know the Eagle doesn't use boom blocks. Just pulp for you to chew on.
Thanks. Brad.
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