Yeah actually it won't hurt the ENGINE so much as it very very well might cause the engine to flood.. If a carburetor is setup to be gravity fed, the needle seat will be made to work that way.. If a carb is setup to run a fuel pump, they will have seats made to handle a fuel pump.. Running a fuel pump on a standard small engine carb will usually cause float issues.. :doah:
It's like 125 said.. If the carb is being fed fine with the gravity feed system, stick with it and wait to start wearing out your fuel pump until ya have something worth putting miles on it for. :thumbsup: