Gas in airbox

[bigs_gs]

Hey guys I'm really glad I found this place, alot of helpful info.

Ok here it goes. I just recently bought a gs850L and It POURS gas out of the airbox. The gas is really dark but doesnt have an oil consistancy to it. It will start but the first and fourth cylinder exhaust pipes stay cold. I replaced the coil on those cylinders cause it was bad. It will rev up to about 2.5k rpm but thats it. When you kill it you can hear a bubbling sound from the carbs. What do you guys think I should do to remedy this problem.

[chef1366]

Is the gas coming out of the carbs dark? Or is it getting dark from sitting in the air box? If you have oil in the gas it could be valve seals. If it's straight gas it sounds like stuck float needle or bad o-rings in the needle seat. Your carbs need to be removed and rebuilt.

http://www.thegsresources.com/gs_carbrebuild.htm

[Redman]

You didnt say what model/year.

Other possibility would be fuel petcock has failed (or left in 'prime' position) and has overflowed the carb bowls and overflowed into air box.

Gas is dark from picking up dirty oil that is also in ari box.

Check to see if you have gas in craankcase.

Tell us more. How is it now?

Welcome to GSR.

[bigs_gs]

Its a 1980 gs850L It faintly smells like gas but not alot when I smell the oil. And like I said I have 2 dead cylinders. Thats the part that weirds me out. I know the plugs are firing and theres plenty of gas but the pipes on those 2 cylinders never heat up.

[bigs_gs]

Ok I took the airbox off so I could better see where the gas is coming from and its not the carbs. There is a hose that goes into the top of the airbox that comes from the top of the engine and thats whats spraying all the liquid. And by spray i mean SPRAY. Its like a torrent. Also for some strange reason today my other 2 cylinders started working but it still won't rev past 4k rpm before it starts backfiring sputtering and smoking like crazy.

[terry]

If you've got gas spraying from the breather hose in your cylinder head back into your airbox, it means that your engine is full of gas, so shut it off now!

Like a previous poster has suggested, either your petcock is buggered, or it's been left in the prime position, and raw fuel has overwhelmed your floats, run continuously into your cylinders, and seeped into your crankcase past your piston rings.

Switch your fuel off, remove your sump plug and drain all of that fuel/oil out of your engine, remove the oil filter as well, install a new filter and new oil. Hopefully the fuel circulating through your engine hasn't washed all the lubricant off your bearings and destroyed them. Hopefully.............

Why isn't it running on all four? Well, apart from the problems mentioned above, you may well have a couple of blocked jets (were the plugs "wet" with fuel in those cylinders?) or you may need to adjust your valves, as a couple might be too tight, causing a lack of compression, hence, no combustion. It could also be a couple of burned exhaust valves, an ailment not uncommon on our engines.

Whatever you do next, don't attempt to run that engine again until you remove all traces of gas from your crankcases, or you WILL destroy your engine! (if you haven't already) Cheers, Terry.

[bigs_gs]

Im new to the gs model and my setting indicators on my petcock are wore off. So where does it need to be aimed to be in the "run" setting. Also the engine doesnt knock or anything like that so hopefully its not ruined. And yes the plugs were wet in those cylinders but I cleaned em thoroughly and now they fire. Also by sump plug are you talking about the oil drain plug? Sorry if I sound a little on the novice side but I'm really new to motorcycle engines. Thanks for all the help guys.
Joe

[Redman]

Thats why I asked if a G or a GL.
Gs (like I have had) have a petcock with obvious lever with PRIme-ON-REServe position. I am not so familiar with teh petcocks on the GLs, but I think its not such a lever, but just a screw driver slot.

[bigs_gs]

Yep I almost thought it was broke lol. Its just a small flathead slot with no writing around the rim of where you insert it.

[terry]

Im new to the gs model and my setting indicators on my petcock are wore off. So where does it need to be aimed to be in the "run" setting. Also the engine doesnt knock or anything like that so hopefully its not ruined. And yes the plugs were wet in those cylinders but I cleaned em thoroughly and now they fire. Also by sump plug are you talking about the oil drain plug? Sorry if I sound a little on the novice side but I'm really new to motorcycle engines. Thanks for all the help guys.
Joe

Yeah mate, the oil drain plug is what I meant by "sump plug". Those petcocks with just a slot are crap, there was one on my GS1000ST, and the "prime" position doesn't even work, so that's not your problem.

However, if the petcock has been disassembled and then reassembled and whoever did it put the spring on the "wrong" side of the diaphram, the fuel won't "switch off" and will continue to flow until the tank empties itself into your crankcases. I'm guessing that's what happened.

From memory (I'm at work today so can't go check that petcock) the "On" psition is with the slot straight up and down, and "Prime" (not that it works) is with the slot straight across. (horizontal) I put a "Pingle" tap on my bike, and it made a world of difference. Cheers, Terry.

[chef1366]

Yeah mate, the oil drain plug is what I meant by "sump plug". Those petcocks with just a slot are crap, there was one on my GS1000ST, and the "prime" position doesn't even work, so that's not your problem.

However, if the petcock has been disassembled and then reassembled and whoever did it put the spring on the "wrong" side of the diaphram, the fuel won't "switch off" and will continue to flow until the tank empties itself into your crankcases. I'm guessing that's what happened.

From memory (I'm at work today so can't go check that petcock) the "On" psition is with the slot straight up and down, and "Prime" (not that it works) is with the slot straight across. (horizontal) I put a "Pingle" tap on my bike, and it made a world of difference. Cheers, Terry.

The petcock postitions are the opposite. Up and down are prime and run is horizontal. (I had to go outside and look) Just replace this pos, it's not worth the hassle. Check out Georgefix on Ebay.

[bigs_gs]

From what I understand the petcock is vacuum actuated and I took my tank off to get the airbox off. The gas never shut off even with the engine not running. Could this be part of my problem? Any help would be greatly appreciated.

[chef1366]

Yes that would be part of your problem. Replace the petcock.

[Road_Clam]

Its a 1980 gs850L It faintly smells like gas but not alot when I smell the oil. And like I said I have 2 dead cylinders. Thats the part that weirds me out. I know the plugs are firing and theres plenty of gas but the pipes on those 2 cylinders never heat up.

If you have bad intake valve(s), this will cause "backpressure" to blow raw fuel and air into your airbox. Try to isolate where the fuel is entering the airbox. A common culprit is the valve cover breather hose. This could also mean you are getting excessive crankcase blowby from bad piston rings.

[bigs_gs]

Yeah thats where its coming from alright. And it POURS. Guess I got had by the dude selling it. But i'm going to be optimistic and hope replacing the oil and fixing the petcock will remedy my problem. Cross your fingers for me.