Just finished up on a guys 74 90.. my problem is that its running rich with the high altitude knob off and I have very limited idle adjustment.. I pull the knob out ( giving it more air) it runs better and I have better idle adjustment.. pulled carb twice, nice and clean and adjusted timing.. starts 1st pull. Oh yeah it has a stock airbox but not a stock filter..
I'm lost but am tempted to leave the way it is.