Motorcycle Repair: 1985 yamaha maxim xj 700 problem, vacuum hoses, diaphrams

Question
hi Bill i have a 1985 yamaha maxim xj 700 bike and recently like yesterday it doesnt want to idle properly, the day before i was riding it and after about 10 mins it stalled its allmost like it ran out of gas but the tank is full, the fuel filter is good and the air filter also. it actually dropped a couple of cylinders that day and acted like it was starving for fuel. today i took the tank off and drined the bowls underneath the carbs and no.1 was completely empty the other three were good but no.1 nothing. i think that is why after about 10 mins of driving it starts acting up because there is fuel there from sitting over night and when i drive it for 10 mins or so the fuel is gone out of the carb and starts to drop the cylinder. recently there is a ticking noise coming from that cylinder where the no.1 carb is. what could it be any help would be appreciated.   thanks.  steve.

Answer
Steve, I am not really strong on info for Yamahanamas..

http://www.powersportspro.com/partsfish/login.asp for references to the parts involved. I see that it doesn't have a vacuum operated petcock, but it does have a large screen for the petcock, up inside the fuel tank. You might get a piece of hose and a can to determine how much fuel is coming out of the petcock. If there are emission controls in place, check for vacuum hoses that may be causing lean conditions on the adjacent cylinders. If the fuel tank isn't being vented properly, it will vapor lock and reduce the fuel flow really fast.

Pull the #1 float bowl and float valve and see if it is being blocked or the needle is sticking in the float valve for some reason. There could be an obstruction in the fuel lines or the interconnecting lines between the carbs.
Also check the carb diaphrams for any kind of tear or rupture.

Bill Silver aka MrHONDA.

The ticking noise could be a partially seized piston, due to the leanout condition on the #1 cylinder.