Hey,
I was just out for a ride when all of a sudden, my bike's sound gets a bit lower in pitch ('thicker' sounding, like it's bogging)... I pull over a block later to find that it's pissing gas out of the airbox hose... managed to get it started and get it back home to the garage (I was only a few blocks from home when I noticed), but it doesn't wanna stop pissing gas unless I turn the tank-mounted petcock to 'off'.
This bike has not been sitting, I ride it daily.
What can cause this? Gonna bet it's gotta be something in the carbs... I had new jets installed about a month ago.
Petcock vacuum gasket might be toast, and your floats aren't stopping the gas efficiently enough. Check your oil too- better safe than sorry.
Quote from: Big Rich on November 07, 2011, 06:21:36 PM
Petcock vacuum gasket might be toast
What's the easiest way to test this? I guess if I detach the petcock from the carburetor, gas should NOT drip from the petcock, and that if it does that means you're right and the vacuum gasket is toast?
If so, I'll test that out tomorrow morning...
Somebody else could explain it better than me- but basically if the engine is not running and the petcock is on, no gas should be flowing.
Just curious, how full was your tank when this happened?
I would say 'pretty f%$king full', touching the bottom lip of the filler neck. If I did overfill it, shouldn't the flow eventually stop? Doesn't look like it wants to, unless I turn the tank petcock off.
I asked about the full tank because on some older Suzuki's the floats can't handle the hydraulic pressure of a full tank. But if the petcock is faulty and you only have half a tank, it won't flood the carbs.
So could anything else cause this? Or are:
#1. Float needle problem.
#2. Petcock problem.
... the only two things that could cause pissing out the airbox hose?
Seems to kind of have a repeating pattern:
- It will flow for several seconds
- Then it slows down, drips for a bit.
- Nothing for a few seconds.
- Repeat.
... kind of like something is filling up, emptying, and then filling again?
So I went out this morning, re-connected the drain hose to the airbox (it came undone while I was fiddling with it yesterday) and drained the float bowls... after draining them I turned the tank petcock back to 'on', and it seems to have resolved the pissing - at least for the moment.
So, maybe it was just some piece of gunk stuck between the needle and it's seat. I know there's a little bit of rust in this tank around the edges (going to do electrolitic rust removal and a new liner this winter), so maybe a rust flake or something.
I'm gonna zip tie my long flathead screwdriver (the one that can reach the tank petcock screw) to one of the subframe bars under the seat and throw a few bendy straws into my tank bag, in case I end up having to do this again at the side of the road.
Quote from: bombshelter13 on November 08, 2011, 08:44:59 AM
So I went out this morning, re-connected the drain hose to the airbox (it came undone while I was fiddling with it yesterday) and drained the float bowls... after draining them I turned the tank petcock back to 'on', and it seems to have resolved the pissing - at least for the moment.
So, maybe it was just some piece of gunk stuck between the needle and it's seat. I know there's a little bit of rust in this tank around the edges (going to do electrolitic rust removal and a new liner this winter), so maybe a rust flake or something.
I'm gonna zip tie my long flathead screwdriver (the one that can reach the tank petcock screw) to one of the subframe bars under the seat and throw a few bendy straws into my tank bag, in case I end up having to do this again at the side of the road.
Doesn't quite eliminate a broken petcock. Fill your tank up again to make sure it's fixed. As suggest, there's a chance your petcock is broken and allowing fuel to go willy-nilly into the floats.
Also:
http://www.amazon.com/Leatherman-830850-Skeletool-CX-Multitool/dp/B000XU43IC
I carry one of these where ever I go. Bailed me out of TONS of sticky situations (one where my battery connectors came loose in a neighborhood that I'd probably be mugged in if I wasn't quicker). Comes with screwdriver tips for you too. Pretty nice.
Since it's been a couple hours since I drained the bowls/enabled the tank petcock, I went out to take a look and see if any dripping had started again (got a bucket under the hose so I can see if any's coming out)... so far everything's dry.
I guess that means that if my petcock is broken, the needle is at least seated properly such that it's stopping the flow.
Would the test I described earlier (disconnect petcock hose from carbs, check for drip in ON position) tell me wether the petcock is broken? Or is there something more I gotta do to determine that?
Dr.McNinja, that's a neat looking tool. I probably have most of the same tools that are on it as individual items in a sidepouch of my tank bag, but the Leatherman would certainly be more compact.
You say 'fill your tank up' - it's still pretty full, I didn't lose that much gas, probably just a few cups. Are you suggesting this because a broken petcock might only show it's flaw with the tank completely full?
Gas dripping from your airbox is almost always due to a float problem. Either your float needle is worn and is no longer sitting properly or you have some debris that is preventing the needle from closing. In order to see gas dripping from the airbox, fuel must be flowing to the carbs.
Fuel flows to the carbs in two situations: 1. The bike is running; 2. The main petcock is set to "prime".
The quick test to see if you have a float problem is to park your bike, set the petcock to "prime" and wait for your bike to start pissing itself from the airbox. If this is happening you must dismantle your carburetors and check the floats for proper operation.
Okay, had a chance to take the bike out for a 45 minute or so long run this evening. So far everything's good, leaking hasn't started again, so hopefully it was just a bit of debris and was caught when I drained the bowls.