genuine walbros will work on any angle usually pump to the top & manifold so it angles up i had no problems at all

make sure u turned the idle screw not one of the low and high ajustment screws

make sure the choke is not (ON) closed !!!! you dont usually need to use the choke with a genuine walbro

as for the fatboy pfttttt they blow chunks & have fitting probs on 50% of bikes & i wouldnt have cut any braces on your frame ya have weakened it
some pics may help tho cant blame the parts its your frame engine mount angle etc....

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