TheBoy wrote:
Saville wrote:
I notice that on a lot of startups - this one, Merlins R-2800's etc - that the prop starts to spin...you can hear cylinders firing...then suddenly no cylinder is firing though the prop is still spinning...but then suddenly the cylinders pick back up again. What causes the pause? Lack of fuel in the lines still? Is that why we see this pilot pumping the primer?
The engine is started with the mixture lean in idle cutoff, so it immediately runs out of fuel after firing. Once it lights, you've got to push the mixture forward out of idle cut off. You can see him do it in this video.
Not exactly sure you two guys are talking about. I'm sure the engine was turned off by pulling the mixture to ICO, so it doesn't run out of fuel once it's running. Let a few blades pass bye and if you don't hear anything strange push the mixture forward. That fuel will be coming from the carburetor, some times a little slowly. When you push the primer in, you're ejecting fuel directly into the cylinders, kind of like a poor man's fuel injection.
FYI - Nice video..
Phil