Hey gang,

So first off thanks again for reading and responding to all these desperate posts!

So I had a carb overflowing into me engine and airbox so I lowered the float heights and reassembled everything. But when I put it all back together I find (through the clean in-line fuel filter to the carbs) that fuel isn't flowing from the the tank to the carbs. I tried all three settings on the gram petcock and even added a couple gallons of fuel since the tank was low.

What the hell happened? Did a floating piece of rust cover the screen on the tank petcock inside? Do I need to have my tank cleaned now?

Too much wrenching and not nearly enough riding..

-RC

If rust is covering the screen, you should be able to shake the tank around and get it to slosh the fuel and move the rust, at least temporarily.  Then fuel would flow for a while.  Did you turn the tank petcock back on?

That's what I was thinking so I sloshed the hell out of the tank and checked tank petcock to make sure it was on twice. I guess next step is yank the tank and and turn its petcock on agaon ad see if it flows out the two hoses?

Quote from: younastytwin on September 15, 2013, 03:07:05 PM
That's what I was thinking so I sloshed the hell out of the tank and checked tank petcock to make sure it was on twice. I guess next step is yank the tank and and turn its petcock on agaon ad see if it flows out the two hoses?

That's what I would do, then maybe check the fuel lines.  Fuel should flow on PRI no regardless, so if it doesn't there must be a restriction.  I guess maybe if your tank vent tube is blocked it MIGHT keep fuel from flowing but I would think it would just slow the flow, not totally stop it.

Get rid of the inline filters.  Some are so restrictive that they starve the engine of fuel.  I tried them for a little while and they caused nothing but problems, I threw them in the trash and all is well.....

So fuel flows out from both hoses when I turn on the tank petcock. I guess now it's time to pull and disassemble the frame petcock to possibly rebuild or replace. Seems weird that it just went out of nowhere, no?

Did you have the inline fuel filter on before you pulled the carbs and adjusted the floats?  If not, I'd pull that off and replace that fuel line first (actually I'd do that anyways for the reasons stated a few posts earlier).  If that doesn't work, then I'd check the frame petcock.

You could also try removing the fuel line from the inline filter on the frame petcock side, and see if gas come out of there.  If so, then the inline filter is probably where your issue is at. (I'd put frame petcock on prime for a bit, then back to ON to stop the fuel flow, then check).

You could have a blob of gunk in the frame petcock.
Or pinched fuel line to the carbs.
Remember that in PRIME, fuel should flow even with the engine off.
Pull the spring clip off of the frame petcock and clean it out. That's all the disassembly needed. No need to unscrew the back from it. That's just the back of the vacuum diaphragm.
I've seen the passages all gunked up and removing the front clip and lever & inner valve cone  shaped thingy will let you clean it all out.
Sometimes it happens if you never use reserve. Gunk collects in the reserve fuel line. First time you use reserve (or prime) all that gunk suddenly moves from that fuel line and clogs things up.

As a practice, I run a bike in reserve for a mile or two after every few fill ups just to keep the line clean and not filled with sludge or water (from the ethanol).

Quote from: adidasguy on September 16, 2013, 05:13:35 PM
You could have a blob of gunk in the frame petcock.
Or pinched fuel line to the carbs.
Remember that in PRIME, fuel should flow even with the engine off.
Pull the spring clip off of the frame petcock and clean it out. That's all the disassembly needed. No need to unscrew the back from it. That's just the back of the vacuum diaphragm.
I've seen the passages all gunked up and removing the front clip and lever & inner valve cone  shaped thingy will let you clean it all out.
Sometimes it happens if you never use reserve. Gunk collects in the reserve fuel line. First time you use reserve (or prime) all that gunk suddenly moves from that fuel line and clogs things up.

As a practice, I run a bike in reserve for a mile or two after every few fill ups just to keep the line clean and not filled with sludge or water (from the ethanol).

TBH my friend on my gs' ive always ran them on reserve but zeroed out the trip odometer. id start looking at 80.

Cleaned the petcock, for what it was worth, and confirmed that it flowed to the carbs. It seems I set my floats so low  that it wasn't filling the bowls. I'd had problems with them flooding into the crankcase/airbox before... I reset the floats (they're at the gasket level on the bowl on the side closest to the engine). One might be 1mm above that line, but that should be fine, right?

So now I've got a little stumble at 4k so I'll sync and check mixture screws as advised on here and get back.