Home › Forum › Ask A Member › Mcculloch 4hp no start › Re: Mcculloch 4hp no start
Okay, well, you’re testing the spark with a spark plug, in both cases. A regular spark plug gap of more or less .030" is not enough to really test the system. It is easier for spark to jump that gap under regular, atmospheric pressure than it is under 90 psi. When you put the plug in the engine, and put fuel and compression to it, it may NOT fire. This is why the spark has got to jump at LEAST….at the very, very LEAST…..3/16" in the open air. A quarter inch is better, and very commonly obtainable.
If you don’t want to make it jump the 3/16", then at least try closing the actual plug gap down, WAY down, to .010" and see if the engine will fart on that.
Also, if you’re trying to start it with the mag lever position in that video, that’s still not far enough over to port. Should be 3/4 of the way over to port. And, when in that position, the actual throttle plate inside the carb should also be opening about 3/4 of its travel.
Long live American manufacturing!