Outrageous amount of gas coming from airbox drain hose

Like the title says, Outrageous amount of gas coming from air box drain hose.

Replaced solenoid, starter and cables for starting problems (which it desperately needed). Wouldn't want to start a few times over the last couple of weeks and I chalked it up to the bike sitting for long periods of time. A bump start worked fine, but in order for it to run smoothly I had to have the throttle wide open or have the choke wide open.

I noticed a large amount of gasoline pouring down from the hose that drops straight down from the air box(the one where the carbs connect), which means the carbs are sending the gasoline out the wrong end.

I am lost as to what to start checking. I though about potentially a stuck float, but would that contribute to the starting problem?

 

Yes it will check oil for fuel contamination also.

 

im almost positive your prob is a stuck float, happens all the time on these carbs. you can try hitting the carbs individually with a hammer light taps to the float chambers and you might get lucky and dislodge the floats so they work properly. if not you gonna have to remove the carbs and fix the problems. mine did this and fuel would pour out the intake side into the airbox, your good just check it out and see. do you know how to test float hight? check the faq section

 

First off, gas doesn't run uphill, so chances are your crankcase is full of gasoline which is pumping out the breather into the airbox.

The very first thing you need to do is check the oil for gasoline; if it's contaminated then it must be changed NOW before you run the engine any more. Take the filler plug off, and stick your nose in the hole and have a whiff. If it smells of gasoline then it's confirmed.

The problem is two-pronged: Your petcock was either left on PRI or it's not shutting off when it should (in ON with the motor off)

PLUS a stuck and/or misadjusted float or floats.

Both have to happen for this to occur. A properly operating petcock is off when the motor's off;
Properly operating floats won't allow gas to flow even if the petcock is on PRI.

You may also find that your air filter has become saturated; FIX the (2) problems first then replace it. DO NOT run the motor if it's full of gas-diluted oil.

You need to figure out and fix this or it will keep happening. Sorry.

 

What's the best way to flush out the crankcase if one suspects that gas may have gotten in the oil / crankcase?

 

You shouldn't have to "flush" the case with any special agent or anything. Just go and get yourself a case of oil and two new filters, drain the crank case, replace the oil and filter, run the bike just long enough to heat it up a bit, and change the oil and filter again.

 

Stop the Flow of Gas.
Install a Plastic Shut-off Valve just after the Petcock.
Briggs and Stratton Valve -- Hardware Store -- 10 Bucks.


Determine the cause of the flooding.
Petcock Leak-by, ... Possible.
Carb Floats.
Float Heights.

The Briggs & Stratton Valve >> STOPS the leak ... Until you determine the cause.
10-Bucks.
Cheaper than dealing with a contaminated crankcase.
Insurance against a Fire Hazard.

 

Thanks! I had the oil change part in mind, but didn't think of the filter.
The reason I ask is because, apparently when I was trying to determine that cy. 2&3 were not firing, gas may have gotten in the crankcase (that's an understatement).
I was gonna fill up 1,5 L and drain (and repeat until the oil that comes out no longer smelled of gas), but if you say 2 twice should be enough, yay to thee.

 

what they said ^^

 

Change the oil and filter first. Run it a bit and check to see if the oil is still smelling of gas. If it is not then I don't know if I would change it again so soon or not.
A GOOD WORD:
If you have dead cylinders gas can pump up and get into the crankcase by bypassing the rings. You should try to do a compression check. If it has good compression, check the ignition system and replace the spark plugs. Once spark plugs get fouled with fuel it is hard to get them to fire again.
Leaking valves, or valves too tight can mimic a carb problem. Nothing like chasing your tail looking at one problem when it is actually something else that is causing the problem in the first place.
In other words, make sure that you have decent compression before getting into the carbs. One way to tell if all cylinders are firing is when you first start the bike and the pipes are cold, quickly before they warm up, tap your hand on them to see if any are not getting hot. If any are not heating up very quickly that cylinder is not firing.
WARNING: Do NOT just grab hold of them because you will leave all of the skin from your hand on the pipes. You must tap them quickly. This will give you an indication of which cylinders to check first.
A lot of people on here can give you some good advice.

 

I'd go ahead and check the needle valves as well, and ensure the rubber tips comes to a fine point.

 

Before you get involved in doing anything of a Tuning or Repair nature; you should look at the results of a Compression Check.

The results of a Compression Check will serve to give you an idea as to the "Well-being" of the Engine.

If the Compression Test gives you results confirming that the Engine is in OK condition, ... or, within the range that considered good-enough to allow the Cylinder to Fire and make Power ... you know you are not wasting time and effort doing other work for naught.

Valuable Information on Compression Testing can be found here:

http://www.aa1car.com/library/compression.htm

 

Oh,

Safety first! I would never advise touching the pipes when they are warm or warming up. You just never know when you might get a nasty burn. My technique is to fill a small spray bottle with water and squirt a bit onto the pipe of interest. Much safer!