Yes, we numerous threads about that subject... Let me get you going on the right path.....
First I have a gx160 with stock tank relocated. This one uses a fuel pump, because I mounted the stock tank next to the engine, below the carb inlet. These fuel systems work on gravity feed, so the tanks new location necessitated the need for a pulse pump. Since I had removed my governor, I installed a fitting in that hole that was left, to attach a hose to send a pulse signal to the pump. The pulse signal is just the vacuum action you get as the engine completes a firing cycle. The piston moving, creates a positive, then negative pressure, as it goes up and down. This vacuum is what actuated the membrane inside the pump, to sucks fuel in, then push it out.....
Now, if you still have the governor intact, you have 2 common options.
First, drill a hole in a certain location of the valve cover. This area provides a great signal for a pulse pump. After drill the hole, you simply screw in a hose nipple.
The other option would be to by a phenolic spacer the goes between carb and engine, and it has a port on the side, to screw in a hose nipple. They cost around $20-25, IIRC, but could be higher or lower.
Now, on my daughters kart, I removed the stock tank for seat clearance. Then I mounted a plastic tank onto the back seat rail. It's above the carb inlet, so it's still a gravity feed system. Now, the only thing with this that you need to keep in mind, is that to operate efficiently/correctly, the tank outlet should be 1/2" to 1" above the carb inlet. The higher it is, the more down force is created. If you go too high, you could end up with excess fuel seepage...... BUT for all intents and purposes, you can safely go up to around 4"-5" and see no real issues.....
My daughters is about 5" away, and not one bit of problems.....
Did that cover the majority of it? I'll post a link to the valve cover hose nipple installation in a bit..... And to the spacer.....
