lots of fuel in airbox

2

2wheelsdown

Scooter
I did a baffletomy on a spare set of pipes and planned on putting them on the bike tonight. I haven't run the bike in a month so I let it run for a few seconds to be sure it was charged but not long enough to get the pipes hot. When I started removing the pipes I noticed a drip and the smell of gas. I traced the source of the fuel drip to the snorkle and when I fiddled with the snorkle the drip turned into a pretty good trickle. I removed the airbox cover and the filter was soaked in fuel and the airbox was full of it. Turning the petcock off did stop the flow but when I turned it back on there was a steady trickle of fuel into the airbox.

I'm a rookie when it comes to tinkering with motorcycles, so forgive me if there is an obvious answer to this problem. Can anyone shed some light on why I have fuel flowing into my airbox?
 
B06Tang

B06Tang

Cafe Racer
First place I would like into is if your float bowls in your carbs are working as they should. A big sign to this is if you are saying you don't have the problem when your turn the petcock off from the tank. Two points of fuel control from the tank to the bows...your petcock and your bowls. Either the float bowls will need to be adjusted or you might have some parts to replace. What year Bonnie is this?
 
2

2wheelsdown

Scooter
sorry, I forgot that important bit of info. It's a 2008 with a few cosmetic mods but the debaffled pipes were going to be the first mod to the engine/drivetrain.
 
B06Tang

B06Tang

Cafe Racer
2wheelsdown said:
sorry, I forgot that important bit of info. It's a 2008 with a few cosmetic mods but the debaffled pipes were going to be the first mod to the engine/drivetrain.
Click to expand...

That's the last year for carbs as far as stateside goes. I wouldn't think you need to start doing part replacement on your carbs with this still being a fairly new bike. My guess is you have some gunked up shit and your carbs could stand a good cleaning. Do you do any fuel prep during the winter months at all or is it just fuel up and go year around? I ask that because I noticed your stats says Alabama. I'm just kind of rifling off ideas as I ramble and type but if you have never conditioned your gas tank at all then you could have acquired a good amount of gunk
 
T

thearcticsea

Rocker
Seems to me like, as Tang said, you have a clogged primary jet, or stuck floats. Fuel is flowing into the bowls and not stopping when it should. One thing to think about is that if fuel is backing up into the airbox then it's probably also backed up into the cylinder.

I would not crank the bike over, as hydrolock can occur. If this was my bike I would also err on the side of caution and drain the oil, checking for gasoline in the crankcase.

Keep us updated.
 
B06Tang

B06Tang

Cafe Racer
thearcticsea said:
I would not crank the bike over, as hydrolock can occur. If this was my bike I would also err on the side of caution and drain the oil, checking for gasoline in the crankcase.

Keep us updated.
Click to expand...

+10,000!

This is good advise and something I should have mentioned as well. I kind of get target fixation once the noodle locks on to something :nose::nose:

But I would definitely drain the oil and do everything to determine if fuel went into the chamber or not
 
Roger

Roger

Street Tracker
What B06Tang said. Now, go to your toilet, take the lid (float bowl cover) off the tank (float bowl). Push down on the big ball (float) a few centimeters. The valve (float valve) at the other end of the rod will start to flow water (gas) into the tank. So your carbs work no different than a toilet really, only that the float bowl is inverse to what you see in the toilet tank.

But we do need to know, how old is the bike, has is sat for long periods (months) and have you ever used a fuel treatment / stabilizer like Seafoam?

If you decide to open the float bowls to take a look, and you see a green film on the parts and in the bowl, you will need to remove the carburetors and clean them properly. The green film is old, stale gas that has dried up and gummed things up.
If there is no green build-up, the float valve or needle could have dirt under it or just not seating properly. Another problem could be that one of the floats is 'heavy' being saturated with fuel and can't float up to close the float valve.

If you use any type of spray carb cleaner, wear eye protection.

Let us know what you find. I'm sure you will find lots of help here too.

http://img17.imageshack.us/img17/800/x8l7.jpg
 
fender

fender

Street Tracker
I had a stuck bowl once. Definitely change out the oil. I also pulled the spark plugs and manually pushed the bike to turn over the engine, with the ignition off. I also did the diagnosing and cleaning of the float bowl ect prior to changing the oil just to make sure I had the problem solved prior to putting in new oil.

Mine was easy to diagnose since once I dropped the float bowl is was easy to see that for some reason it got stuck. But after thorough cleaning with carb cleaner and I've never had a problem since. I also almost always use the fuel petcock to shut off the fuel supply when sitting.

Good luck with diagnosing it.
 
N

normandy

Street Tracker
I would guess it is a stuck float needle valve. Easy fix. Just drop the float bowl on the carb that is running out fuel, remove the float assembly and the valve is there. Clean it, reassemble being careful not to alter the tab for float height. Before putting the float bowl on, put a container under, lift the float, turn on the gas and work the float up and down. The fuel should stop and flow. Now you must change the oil and air filter before running as noted.
 
2

2wheelsdown

Scooter
Thanks for all of the advice guys. I was thinking it was something stuck open in the carbs, but I would have never known to drain the oil before cranking again. This sounds like it could be pretty involved and I don't have a garage at the moment, so I might have to let the shop take a look at it. I'll take a look myself first and see if I think I can sort it out.

A couple of questions that I didn't answer before: the bike is a 2008 and had been sitting for about 1.5 months since last run. I had run some seafoam through it back in February to get it running smoother for the summer but then only road occasionally during the summer. The gas that was sitting in it this time was maybe three months old but did not have any treatment in it.
 
B06Tang

B06Tang

Cafe Racer
Just out of curiosity but did you leave your petcock turned on when the bike was sitting for the 1.5 months?
 
2

2wheelsdown

Scooter
B06Tang said:
Just out of curiosity but did you leave your petcock turned on when the bike was sitting for the 1.5 months?
Click to expand...

No, the petcock is always off when parked. I turned it on when I ran the bike for about 15 seconds before starting to change the exhaust. I did not turn it off then and that's when the leak started.
 
B06Tang

B06Tang

Cafe Racer
I think a good & thorough cleaning will be your ticket. Hopefully this didn't flood into your chambers. Please ping back to follow up with the outcome. These are great reference materials for down the road
 
2Monkeys

2Monkeys

Street Tracker
I had a similar situation of fuel pouring out of my pod filters while I was working on getting my jetting right. It turned out that my needles were not seating all the way down (my fault for running dynojet needles up too high) and fuel was going up around them and then leaking out thru one of the little holes in the back of the carb. I did (and one always should) change my oil just in case, but I didn't detect any fuel in my oil. My solution was to change back to the stock needles and the leak stopped.

So I agree with the rest of the advice in this thread. Change your oil after you sort the leak, and a good carb cleaning is likely the ticket. Hopefully just some junk under the needle. Best of luck.
 
TC_Dick

TC_Dick

TT Racer
I had the same problem a couple years ago - gas dumped into the airbox and fouled the oil. I had a float that was out of whack. Adjusted that (a couple times), and got it done and good to go.

An easy check for that, if you have a centerstand or some kind of stand that will allow the bike to sit level:

  1. Get maybe an 8" piece of plastic tubing, the size that fits over the carb bowl drain nipple thing, long enough to hold up against the bowl while it's attached to the nipple.
  2. Turn off the gas at the petcock.
  3. Attach the tubing to the nipple.
  4. Hold the tubing up against the side of the carb, perpendicular to the ground.
  5. Open the carb bowl drain screw with an allen wrench.
  6. Check the level of gas against the bowl seat, should be +1mm or so.
  7. turn on the petcock
  8. see if the level changes
  9. Repeat on the other carb.

If any of my directions don't make sense, this dude has a pretty easy to follow youtoob clip:

http://www.youtube.com/watch?v=PHuB1lyagKM
 
2

2wheelsdown

Scooter
Hey guys, just checking in to let you know that I haven't forgotten to update, I just haven't made any progress. I'm hoping to get on it this week.
 
2

2wheelsdown

Scooter
Finally got the bike running right again. It took a couple of carb cleanings and a new needle valve on one side. I also re-jetted in the process. Lesson learned about not letting gas sit in the tank.
 
2

2wheelsdown

Scooter
Motley said:
How come it took sixteen months?
Click to expand...

It really only took the past two months to sort it out. The first 14 months were spent getting ready to fix it! Really it involved not having a shop, buying a new house, moving, setting up a shop, etc. Lots of excuses, but no motivation to fix it for a while.
 
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