Here is a good one for all you 617 fans:

The SD has been in the garage for about three weeks or so. I've been driving the SDL because the SD needs a head gasket and I haven't the time for it.

So, I figured I'd take it out for a spin on Sunday after cleaning out the second garage bay. I glow it for 10 seconds or so and it starts right up. Feels a litttle sluggish and does not really want to rev. Settles into a steady idle. 20 seconds later it dies flat. No sputter, no dropping of revs. Just out. Like a gasser without spark. Crank it. Nothing. Check for fuel. Good. Drop secondary filter. Good. Hit primer pump a bunch of times. Crank again. Nothing. Check for fuel at injectors. Seems to leak out of cracked lines. Tighten lines. Not even a hint of fire.

I have solved it.

Anybody want to hazard a guess?

A hint: about 4 gallons of fuel in the tank for three weeks.