Small Engine Troubleshooting Problems? Ask a Mechanic Now.
First I would test the cylinders! Loosen the spark plug wires, then with engine idling, remove one wire at a time,engine should continue to run, If engine dies when one wire is removed, the opposite cylinder is not firing. If not firing check for spark. No spark on kawaski is usually a bad coil. If engine does not have dead cylinder, then the surging is a lack of fuel, check the fuel supply from tank to the fue pump.
Was engine surging when test were done? Did you try a test line from the fuel pump inlet, back into the fuel tank filler, to see if it is fule supply problem?
Does adding choke make any difference? Have the valves ever been adjusted? .006 inch. intake and exhaust
oK> So it is not always doing it.??