Small Engines (Lawn Mowers, etc.): 1985 yamaha tri-moto atv, gravity fed, vacuum system

Question
is there a vacuum system that pulls the fuel to the carb or is it gravity fed? because it will run on carb spray or when we put gas directly in the carberator, and the throttle works.we also cleaned all of the lines and there is no blockage.

Answer
Hi Lenny,

I'm not sure what carb type your atv uses.  Some have a vacuum pump, which if equipped, would be located between the carb and tank.  Otherwise the engine's vacuum draws the fuel from the carb.  If it will only run when you add fuel to the carb intake then there is a blockage somewhere.  Recheck the carb by disassembling and cleaning it internally, probing each and every hole with a small wire. Finally blow it out with compressed air. Adding a carb rebuild kit wouldn't hurt either.

Let me know how you make out.
Michael