I think it just needs a boat ride now. Exhaust inhalation is definitely preventing good idle quality in the barrel. In have the top of my barrel wide open and a big shop fan blowing exhaust away. That helps, but anything over a 5.5 can be sketchy dialing in a good idle. Your splash shield definitely helps contain the water, but it directs exhaust right to the intake silencer. I think all you need is open air like you mentioned to make it right. Looks like a good one.
-Ben
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