That dreaded CARB word!

[jtcrespo]

Bike is 83' GS750 ES that hasn't run in two years.

work done so far:
carb rebuild due to rust in system, float levels assumed to be correct, but not ruled out, all fuel lines new and connected correctly, fuel tank cleaned and sealed, petcock working well.

Symptoms engine is showing:
Starts fine, warms up fine, then idle jumps to 2000rpm for 10 seconds, and comes down to 800rpm or stall, then repeats if running. Can be kept running, pulls strong on low end, a little surging around 4500rpm, but fine on into higher revs.

Here is where it gets tricky for me; There is a breather tube that is connected to the top of the engine on one end and supposed to be attached to airbox on other end, there are K&N pods, so no air box, tube end hangs open above carbs currently. Once every 5 seconds, a drop of fuel comes out of this line and there is a strong smell of gas.

I know that this problem is usually either needle valve(s), float level(s), or poor synch. The leaking breather tube really perplexes me. There is no diagram for it in my manual. There are no fuel leaks anywhere else in the system and everything seems to be working fine.

Any ideas on what may be going on?

[Anonymous]

Gas? Hmm. I'd expect some oil mist or even a drop of oil, but not gas... Have you changed the oil? Is it possible the PO let fuel get into the crankcase (via the carbs)? Oper the filler cap and check for a strong oil smell. If its sat for that long an oil change is called for anyway...

[jtcrespo]

Changed oil, but fluid is clear and not oil. Could it be condensation mixed with gas? I'm just throwing out anything here. I'm stumped.

[Anonymous]

"Strong smell of gas" still sounds like there's gas in the oil. Are you sure all of your overflow vent lines from the carbs aren't pinched or plugged? Sounds like a float might have gotten stuck, and instead of fuel draining out the overflow, it made it's way thru a carb, past an intake and into the case.

[jtcrespo]

I'll check that out