97 new needle and seats, carbs cleaned, new air filter, fuel filter,and new battery road for 2hrs yesterday shut off a couple of times once goin down highway. thought it was a kinked gas line coming from petcock to fuel pump fixed and got me home. went to crank today and gas started coming from i think a bleed off line, but still wont start.
SOURCE: 1985 Yamaha xj700 Maxim- Carb. fuel lines
yes, the breather line hooks to the petcock on the line facing the back, the fuel line hooks to the larger one. the line from the breather is actually a vacume line that turns on the fuel, without it you will not get fuel out of the petcock unless it is in the prime position.
SOURCE: engine flooding gas building exceessive pressure
Remove the fuel cap and try it. If the problem disappears, you need a new cap as the vent has become plugged up.
SOURCE: My yamaha yzf600 sat for 3 years, it will idle but
You'll need to disassemble your carbs and manually clean the jets, and ensure that if you have CV-type carbs, you can see all the needle holders rising when you roll on the throttle.
SOURCE: Working on a friends 81
The petcock on these bikes is vacuum operated, which means that there are two hoses that go to it. The thicker hose is the fuel line and it runs from the thick port on the petcock to the fuel input on the carburetor rack. The fuel input on the carburetors is located between the number two and number three carburetor bodies. If you aren't sure which is the fuel connection, just turn the petcock switch to prime for a second and you will see gas come out of the fuel connection.
The thinner hose on the petcock is a vacuum line. It runs from the vacuum port on the #3 cylinder (between the carburetor body and the engine) up to the smaller connection on your petcock. When the engine is turning vacuum is applied to this thinner line and allows fuel to run from the tank into the carburetors.
There are the only two lines that should run to your petcock, and the fuel line should not be split anywhere between the petcock and the carburetors.
Good Luck,
-Josh
Testimonial: "Thank you for the feedback, It was very helpful. I had been told that both ports on the intake were to be plugged, which added to my confusion, Ted"
SOURCE: i have a yamaha 650
Cleaning the fuel tap and any filter on it would be a positive step. Also check the fuel hose that it is clear and that the float needles and seats are opening and allowing gas into the float chamber.
Testimonial: "im gonna try what you said. but could it be the petcock????"
711 views
Usually answered in minutes!
If the gas is coming from a carb bowl overflow line, then one of your floats is probably stuck open. This would also flood one cylinder so one of your plugs should be wet after riding.
×