hey guys, i have been tackling a small go-kart to try and get it running. it has a 5hp b&s horizontal shaft engine with a pulsa-jet carb. the engine wouldn't start initially when i began, but i finally got it to run somewhat..had to replace the plug, head gasket was blown, and i replaced the diaphragm in the carb and also cleaned it out good..i noticed there is some rust in the fuel tank, but i cleaned it up pretty good by putting a few handfuls of nuts and bolts in it and shaking the s**t out of it, then rinsing it out. OK now on to the problem.. it acts like it is not getting gas. it starts and runs, but only idles, when i try to crack the throttle at all it gets doggy and bogs out unless i partially choke it.. then it will rev up as it is supposed to (black smoke and all), but then starts gagging and bogging out again..it will run fine and idle good without choke.. everything seems fine, and i just cant understand whats happening..its pumping fine because when i pull the carb off the tank, the little bowl is always full of clean gas.. what to do next?

ok, the pickup tubes may be a little clogged, and of course the adjustment screws may be out of wack, hense a adjustment.

Since you have cleaned the tank and the small tank has fuel I would think the tank is clean and the pump is working but be watching for the rust to return and clog the main pickup tube. These tanks are notorious for this problem. I sure wish they made an affordable stainless. Is the small pickup tube screen clean? These can look clear but be varnished over some and you can lose some flow there. If this is an adjustable jet carb have you taken the main brass jet out and cleaned the holes behind it? There is a large and small one. Just to make sure on this, the pump spring goes in first, then the spring cap and then the diaphragm. One problem with this carb is a diaphragm cover that doesn't seal completely. You can take the guide pin out of it and run it over some sandpaper on a flat surface and sort of "deck" it. Also, try running 2 carb to tank gaskets, I've seen to many with a slight bend in the tank that you can't see and cures a carb base that may be out of whack. You can also boil this carb over night because there are no seals that will be damaged.

Is this the later model fixed jet or older arrow or pull choke carb?

Check some of these things and let us know how its going.

Mike

my carburetor is just toast...its cracked and one of the flanges where it mounts to the engine is broken so its not pumping fuel..if anyone has a pulsa jet carb for a 5hp briggs horizontal engine, mine is not pull out choke, its lever and has a adjustment screw, let me know or if you have something that would work, email me at Racing666@sc.rr.com..i really wanna get this going for my girlfriends little sister to mess around on....(also i wanna ride it too!)

Dennis