I'd like to pick your brains for a bit...Yesterday I continued working on my '84 VF500c. I filled the carbs with gas, placed the choke to the on position, and started the bike. It started, and ran for about a minute or two, then quit. I tried to restart it without success. I opened the drain on all of the carb bowls, and fuel poured out. So I filled the carbs again, and it started up and ran for another minute or two, then quit. Do the carbs need to maintain a certain fuel level to continuously run the engine? If so, then it sounds like I have a bad fuel pump or petcock. If the carbs do not need to maintain a certain level of fuel, what could be my problem?
(I should note that when the bike ran, white smoke was pouring out of the exhaust. I don't know if this is a related issue of not. I am pretty sure the head gasket need to be fixed, though)
Carbs do require a certain amount of flow to work. You can check your fuel pump in a couple of ways. To check the electrical side of it put your hand on top of the pump and turn the key on, you should feel and hear the pump click a couple of times. To check flow remove the fuel line on the left side of the bike just under the main tank and run fuel into a measureing container for 5 seconds. Multiply that amount by 12 and you get the amount per minute of flow. Dont know the number of the top of my head but there is a procedure on how to do it in a repair manual. Also you need check the fuel filter and may need to clean the carbs.
gleaned from the web...
Blue smoke is primarily from internal engine wear. If it's constant when the engine is on, then the rings etc are worn and need to be replaced. If it only is blue when the engine is cold or first started, the rings are worn but not gone completely. You get the oil seeping during the night and it burns off when the car is started in the morning.
Black smoke is a fuel/air mixture suggestion problems with injection or carburation. Cause of black smoke is due to running rich in the fuel air mix.
White smoke can and DOES come from coolant burn off in the oil due to a leaking or blown head gasket, cracked head etc.