Fuel petcock ?

[dr_fosg8]

Ok, I was having some goofy spark plug coloring that was like this. 1,3,4 were all looking like a bit lean, kind of greyish. All the while 2 was always black and wet. I believe I answered why from another post I found while searching the forum. The vacuum line that opens the fuel petcock comes from carb 2, so I was thinking, like the guy in the other post that carb 2 was pulling gas through the vacuum line.

Before I get into this too far. The bike is an 82 gs1100gl. So far I have cleaned the carbs twice, set float height, replaced intake boot o-rings, checked and fixed valve clearances, sealed up the air box, and new plugs and air filter.

So here is what I have done. I pulled the vacuum line off the petcock and plugged it and went for a ride with the tank set to prime and WOW, what a difference, no more surging, and no more rough running over 5k RPM.

Now for my question, will this hurt anything to run on prime and switch to run when parked? Am I going to leak fuel from the vacuum port of the petcock while running on prime?

And btw, I cleaned no.2 plug before the ride and it was burning similar to the rest of the cylinders now.

[PAULYBOY]

My original petcock leaked thru the vacuum port enough to contaminate the oil with a LOT of gas. No matter which position I turnewd it to, it would keep feeding. I bought another one, which was for the wrong year (another story) and just plugged the vacuum fitting to be sure it wouldn't happen again. I turn it ON ( straight up and down) to turn it off, and run it on the 3 oclock postiton to ride. Works great. Either way you go, just go ahead and buy a new petcock, don't fall for the rebuild kit, you'll probably just waste ytour money like many of us have.
Oh, and BTW, to test the petcock the way I use it, I have a tee in the middle of my fuel line, and tested it both ways into a glass jar. Up and down, no fuel, 3 oclock, fuel flows. Just gotta get in the habit of turning it off when I'm done.

[robertbarr]

Now for my question, will this hurt anything to run on prime and switch to run when parked?

No, that shouldn't hurt a thing, unless you forget to switch it. Keep in mind you won't have any Reserve setting.

Am I going to leak fuel from the vacuum port of the petcock while running on prime?

I doubt it, but keep an eye on it. You could always plug it with a short length of blocked vacuum line.

Looks like about time to order a new petcock.

[dr_fosg8]

Thanks for the replys guys. Another question, I am planning on ordering the new petcock now, and a new o-ring for it. Is there any other bits I will need to change it?

[Guest]

petcock bolts have washers/seals on them
may be a good idea to get a new ones