O.k. I am an idiot! Somebody needs to confinscate my tools.

I thought my vac line had gas in it so I cut the line, plugged both ends, switched to "prime", and took her out for a spin. About a minute later my bike sputtered and then died. I couldn't start the thing. I pushed it back home scratched my head and looked really close at the hoses coming off the petcock. You guessed it. I had cut and plugged the FUEL LINE! Savages don't run so well without gas it turns out. Anyway, after I reconnected the fuel line the bike started up fine. I checked the other hose (the real vac line) and it was dry. So... now what? Should I still run it on prime to see if it acts up again? If it does, what does that mean? I am also wondering if my new Dyna muffler is adding to the problem. My engine had bogged down before the muffler switch, but never enough to kill it. I am tempted to put the stock muff back on to see it makes things any better.

Thanks again for your help.

Sandy,

So if it runs o.k. on prime, what does that mean? Any thoughts about the new Dyna being part of the problem?

Doug.

Doug:  If it runs on prime, but not ON or RES, a problem with the petcock is indicated.  The petcock operates on vacuum supplied by the engine.  The vacuum causes a small diaphragm inside the petcock to pull open a valve, allowing fuel to flow when set to ON or RES.  If that diaphragm becomes defective (a hole in it or a stiffening of the material from which it is constructed) it will not maintain a constant open state of the valve.  This, of course, causes the carb to run dry and the engine to starve.  The PRI setting opens the valve mechanically, allowing fuel to flow regardless of vacuum (provided there are no other obstructions between the tank and the spark plug.)

I haven't wrapped my mind around it yet, but I'm told that engine vacuum is at it's lowest at wide open throttle.  Until I understand that, I accept it on faith.  At the same time the vacuum is at its least, the engine is demanding the most fuel.  If there is a flaw in the petcock, these factors combine to cause stumbling or stalling.

If the new muffler is less restrictive than the old one, I would think you would be hearing some backfire activity while the engine was stumbling.  I'd look at the fuel delivery system before I started trying to fix the trouble by changing exhaust.

If you had a bellyache, would you change your diet, or your toilet paper?

Franch:  It MAY be good enough, but you won't find out that it wasn't until your oil is ruined by gas that has leaked by into your sump.  This will at least cost you the price of an oil change, and at worst will ruin your engine.

What's the history of your bike?

Oh, and I drilled out the brass plug and turned the pilot air screw out a turn.

I think it is time to get my hands dirty and see what makes this bike run. I took it out this morning and it killed twice during an hour long ride. Humming right along at sixty five mph and it just died.  It started up after the fourth or fifth try with the starter, only to do it again 20 minutes later. Any ideas where I should look first?

My wife says "just take it to somebody who knows what they're doing!"
She doesn't  have much faith in my "fixin' abilities"...either that or she has a good memory!

Wish me luck!

Ed,
  I hadn't thought about the gas cap. I put a new fuel line on after I cut the old one (thinking it was the vac line). It seems like the problem is gettting worse though. At first the engine would bog down a bit a few times and then get better. But on this last ride it just killed without any warning.

ATP, how old's the battery?

a weak battery will turn over the engine but not have enough juice to get a spark.  (BTW: plugs usually come gapped already)

Take your spare plug, plug it into the sparkplug lead, hold the sparking end against the head (with insullated pliers yn) and check for spark.  No or weak spark means you need a new battery.  this is why you're able to push start it, cause you are not using the battery to turn the engine.