Re: Motor suddenly dying

Posted by HH56 On 2023/4/28 10:51:46

Also, if it turns out to be fuel related and the items already mentioned are OK other possibilities are sediment in the tank was stirred up and is blocking the end of the fuel line pickup tube. If particles were small enough to pass the tube inlet, if there is an electric pump they could have affected the pump or if there is one, clogged its inlet screen or filter. Small particles can also pass thru and clog the screen in the bottom of the mechanical fuel pump.

Another possibility is a rust pinhole in the pickup line inside the tank. This is a known issue that can show up if the fuel level drops below the pinhole. One point is slightly less than half full and the other is a point just about 1/4 full where the inlet tube has a U bend. Once fuel drops below the pinhole the pump sucks air rather than fuel.

One other cause of starting failure when trying to restart a few days after a successful run has also been known to happen if the engine ran on stale fuel. Something -- probably an additive -- in fuel will apparently deteriorate after prolonged sitting and can turn to a glue like material. This coats the valve stems and in some cases after the engine cools has hardened so completely a valve is truly stuck in a guide. If all else is ruled out it might be worth doing a compression check to see if stuck valves are a possibility.