Before you can fix the problem, you must identify the problem.
Take a paper towel and dry everything. Then have a friend bump the starter until the leak starts. Possible leaks:
Split airhorn casting
Defective airhorn thread
Defective fitting
Wrong fitting
Missing gasket (if used)
Defective flare on fuel line
Determine which of the above is the culprit, and repair. If all parts are good, no sealer of any type is necessary.
Based on your posts, my guess is that Wrenchbender is correct in his diagnosis.
Jon.