Never had a problem with the tank not being high enough on those old mules. Are you sure that you did not pinch the fuel line when you routed it behind the flywheel? Also, if you used fuel line which has a wall thickness which is too large. This will cause the line to pinch together when routed? From your description I’m guessing we’re missing something simple.
I would use an in-line spark tester, see what it looks like when you first start and the blower is running well, then, go ahead and use it, if it starts to sputter look at the tester and if the spark seems to have a miss. If so replace your plug, if it still happens replace your coil. Regarding fuel flow from the tank, it doesn't need to be much, trust gravity on that one.