I have a 82 GS850, and only when running it leaks gas into the airbox from the hose coming from the engine to the airbox. This will occur after it has ran for 4-5 seconds. I can turn it off, and it will restart, and 4-5 seconds later it will start leaking. It will dump up to a 1/4 gallon after just one start. When I took off the plugs they were covered in gas and/or oil, and wet. When I changed the oil there was also fuel in the oil. I never do have a problem getting it started or idling. It runs very smooth and does have a little white smoke coming out of tailpipe. (possibly from sitting so long, about 3 years). Here is what I have done.
1. Put in new gas.
2. Removed and cleaned the carbs.(did not dip them)
3. Changed oil
4. changed spark plugs.
5. Put in new passage plugs in the carbs.(one was missing).
6. Caught it on fire, banged my head and repaired damage after fire.
When I got the bike(for a mere 150.00) I was told that the CDI was probably bad but he wasn't sure. He said it had never leaked gas in the past until after sitting so long. I guess I really need help here if anyone has any clue what is going on. After checking the petcock, it only seeps fuel when set on prime. on/reserve only work when cranking engine(vaccum driven). Also I need some new hoses for it between airbox and the carbs if anyone has any. I guess I was thinking if the spark isn't good enough then the cylinders would flood with fuel and be pushed out the the airbox but I am really not sure. Any help would be greatly appreciated.
If I can't do it, I find someone who can.