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gas tanks requires burping
Posted: Thu Jun 24, 2010 4:44 pm
by flw
My kawasaki 500 LTD (en500c-07 w/12k miles, always use premium) and a vacuum build up in my gas tank untl the carb is straved. I burp the tank, wait about a min and it starts and I'm off for another 6 plus miles. Even when pulling upto my home and turn it off I can still burb the tank. My bike has a history with this from other users but I cannot find the work around.
Help with the cap or hose or something else, Dan
I really need your help as the problem is intermidiate and next to impossible to show a mechanic because of this.
Help, Help, Help, Help, Help, Help, Help, Help, Help, Help, Help, Help, Help, Help, Help, Help,

Re: gas tanks requires burping
Posted: Thu Jun 24, 2010 7:12 pm
by Johnj
Sounds like the vent is clogged.
Re: gas tanks requires burping
Posted: Fri Jun 25, 2010 12:35 pm
by Gummiente
I agree with John about a plugged vent. Depending on the bike, some have a vented gas cap and some have a vent hose with a one way check valve; both allow air to enter the tank to fill the void left by the gas as it drains into the carbs through normal use. Over time the gas cap or vent hose will plug up and prevent air from getting into the tank; this will create a vacuum that eventually overpowers the weaker gravity fed fuel stream and causes fuel to quit flowing altogether. When you open the gas cap and "burp" the tank, you are allowing air to enter and equalise the pressure/vacuum inside the tank so that fuel can flow again.
So... change the gas cap or replace the vent hose, as applicable, and the problem will go away.
Re: gas tanks requires burping
Posted: Sun Jun 27, 2010 4:45 pm
by flw
Since I could restart the bike by just removing and reinstalling the gas cap, I agree on a venting issue via the cap and not a clogged intake hose. I also checked the hose just in case, as its simple to check and is just as likely but it seemed fine.
I dissasebled the cap and shortened one of the springs inside that is sappose to allow outside air in when the engine runs. This did the trick as I tested it today. The problem was also temp dependent. the warmer it was the sooner it happened.
I can only assume that each mfg uses a slightly different design (but same principles) for their gas caps so I didn't reference which spring I shortened. As yours may be different than mine.
Dan