Gas leak?

ecurbd02

New Member
May 22, 2008
94
1
0
After every run with my 91 blaster we have to set a pan underneath the engine when i put it away. Im pretty sure that my vent line is leaking after i turn it off. I turn the gas off everytime i put it away but a full carb of gas seems to leak out whenever it sits, after a while it stops, what could be the problem?
 
you sure your turning the petcock to the off position? is your tank cracked? look over it and check ur seal between the petcock and the tank.
 
Could be a dirty vent line causing it to bleed out when not running, or the float is set wrong, making it call for more gas in the bowl than it needs, which in turn shoots it out the drain tube. It may also just be that the float needle is dirty and not seating all the way, causing the above conditions.
 
i know for a fact that the tank is not cracked and the gas is in fact turned off, but i am unfamiliar with the float issues, i know what there float is and where its at but i dont know what i am looking for to determine if it is messed up.
 
heres how i do it pull the float bowl off and turn carb upside down the look at the float and line it up straight and level with the main jet screw in hole (take main jet out) then there is a metal tab on your float that the needle's little metal square things lay on push that tap down gently and just alittle bit until the float is level hope that makes sense. it made sense to me.
 
ok i thought i knew what you meant but i didnt lol i took it apart and looked at it but didnt know what i was doing,and its still leaking gas lol
 
its prolly comming out of the carb overflow tube...and it will do that if you
1)have a bad needle valve and seat...it will just keep pushing fuel through the carb evern if the float sais not to, (gravity from tank) and overflow fron the tube at the bottom of carb
2) float adjustment off...not raising up enough to shut fuel off from needle valve...
id check the valve and seat first
 
or you might have some gunk or rust or something pluggin up the float valve, making it stick open. try disassembling and cleaning the assembly.
also, u sure you're not leaking at the petcock?
 
yea i cleaned my carb pretty well, so i know its not gunk and whichever tube is the long black one coming from the float bowl, not the two short ones on the sides, is the one that its coming from, 100% sure, im not too familiar with part names, i dont understand what u meant by bad needle valve and seat, u might have to put this in retard language for me or get a picture lol
 
lol.....go to the yamaha oem parts site and type your bike year and model up..look on the carburator parts diagram and youll see what the needle valve is, it sits just under the float assembly..its what shuts off the fuel to your carb when you carb bowl gets the correct amount of fuel in it....and by the sounds of it thats what yours isnt doing. which causes gas to either drip or run out of the overflow tube that comes from ther carb..youll see a puddle on the floor everyday from it...also it can cause your bike to get too much fuel sometimes and flood the cylinder/pipe with fuel..if its real badley wore.
hope that halps..
 
Last edited: