Re: Nissan 5hp Issues
Your problem could be almost anything, so start with the basics... Fuel, Ignition, and Mechanical. The NS5B is pretty bulletproof mechanically, so the most effective, quickest and easiest things to verify are spark and gas. If it "just stopped" without any unusual sounds, etc., you may have lost ignition, or stopped delivering gas.
If you have a Factory service manual, cool... that gives ohm readings for the ignition components. Verify that the stop switch is not killing the ignition. If the black and brown wires to the stop switch are connected electrically, the magneto is grounded out, and it will not fire. Even without a Factory service manual, you can pull the plug, inspect its condition (tells volumes about running conditions), and then hold it to block ground (with a glove-insulated hand) to see if you have spark when cranking. If not, you need to troubleshoot the ignition system.
Assuming you have spark, verify gas. Fuel flow can be verified by disconnecting the fuel hose at the carb and turning on the gas ****. If fuel flows, you have gas to the carb. Also make sure that you don't have any water in the gas. If fuel flows OK, and there isn't water in it, the next step would be to see if the carb is mixing fuel and air. If a bit of debris made it through the fuel line, it could clog the float needle. Checking that will require pulling the carb and disassembling it for inspection.
