617: test your knowledge

[Brian Carlton]

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.

[leathermang]

Gas cap vent? Would have said water but you say fuel good....

[Brian Carlton]

Dammit Greg, you are good!!!!!!!!!!!

I cracked the cap, heard a huge whooosh, and then started it right up.

But, why did the tank have such a vacuum after sitting for three weeks? That's what is baffling me. The 617 never gave a hint of tank vacuum problems in the past.

[Tirebiter]

Nice call Leatherman. I've had insects plug off vent lines before and had to use compressed air to clear it.

[JamesStein]

Perhaps you have an algae problem. The algae in the tank is consuming oxygen causing the vaccum.

(just a wild guess)