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i have another ???? air leak around gas cap

Posted: Thu Feb 26, 2009 8:24 pm
by chrisfzr1000
the lip on my gas cap is a bit bent and some times i hear a air leaking noise from it will that hurt the performans..i chang the plugs because some times the bike seems like load up and not run rite for a few min but then cleans it self out the guy i bought the bike from told me he keep getting the tank sealed a few times not sure why but he also put a big ass in line fuel filter on it the rim of the tank on the cap has a small bit of rust anyone have any ideas.. you guys have been a great help so far thxs alot.. chris WOOT

Re: i have another ???? air leak around gas cap

Posted: Thu Feb 26, 2009 9:41 pm
by shredex
mine doesnt fully seal either...when my bike falls on its side, fuel just rushes out.
the gas cap shouldnt effect performance.
you can ride without a gas cap if you wanted to, but that would be dumb.
and you need air to go in there to replace the fuel after its sucked threw to your motor.
like, if you take a straw, put it in a glass of water, and put your thumb on the top and lift it out, the water stays in the straw, but when you let go the water flows out...
if no air could get into your tank, then fuel wouldnt flow from it..

Re: i have another ???? air leak around gas cap

Posted: Thu Feb 26, 2009 10:35 pm
by the_finch
shredex wrote:mine doesnt fully seal either...when my bike falls on its side, fuel just rushes out.
the gas cap shouldnt effect performance.
you can ride without a gas cap if you wanted to, but that would be dumb.
and you need air to go in there to replace the fuel after its sucked threw to your motor.
like, if you take a straw, put it in a glass of water, and put your thumb on the top and lift it out, the water stays in the straw, but when you let go the water flows out...
if no air could get into your tank, then fuel wouldnt flow from it..
A little air leak should not hurt anything, as long as while you are riding fuel does not splash out of the tank. I would be a little concerned about the rust if it was anything more than minor external surface rust. If it is internal, most radiator shops can clean out and re-seal fuel tanks, and the ones in my area quoted me between $65-75 dollars to do the 600's fuel cell. my2cents

On a related note, a friend of mine has a Hyosung GT650S that was apparently manufactured without a tank vent. It would run fine for about 15 minutes and then just die, and if you pulled over and took the gas cap off it would suck alot of air into the tank and run fine for another 15 minutes or so. They had to recall the fuel caps and replace them for free for all of the owners.

Re: i have another ???? air leak around gas cap

Posted: Thu Feb 26, 2009 10:36 pm
by 95FZR600
I would get that lip fixed. It could cause other problems like rust and or performance issues.

Re: i have another ???? air leak around gas cap

Posted: Fri Feb 27, 2009 5:50 am
by yamaha_george
the_finch wrote:
On a related note, a friend of mine has a Hyosung GT650S that was apparently manufactured without a tank vent. It would run fine for about 15 minutes and then just die, and if you pulled over and took the gas cap off it would suck alot of air into the tank and run fine for another 15 minutes or so. They had to recall the fuel caps and replace them for free for all of the owners.
Finch ,
I had a related problem to this on a customers DT175 that had a vent hose running from the cap top to the handlebars with a one way valve on it.
The bike to would stop every 10 mins or so and it was for ever in the shop where it would run perfectly., trouble was we could not send the owner back to his manufacturer as the silly fool kept tying the vent hose in a knot as he thought it looked untidy :headscratch: :duh: banghead screwy :swear

Re: i have another ???? air leak around gas cap

Posted: Fri Feb 27, 2009 7:19 am
by 95FZR600
yamaha_george wrote:
the_finch wrote:
On a related note, a friend of mine has a Hyosung GT650S that was apparently manufactured without a tank vent. It would run fine for about 15 minutes and then just die, and if you pulled over and took the gas cap off it would suck alot of air into the tank and run fine for another 15 minutes or so. They had to recall the fuel caps and replace them for free for all of the owners.
Finch ,
I had a related problem to this on a customers DT175 that had a vent hose running from the cap top to the handlebars with a one way valve on it.
The bike to would stop every 10 mins or so and it was for ever in the shop where it would run perfectly., trouble was we could not send the owner back to his manufacturer as the silly fool kept tying the vent hose in a knot as he thought it looked untidy :headscratch: :duh: banghead screwy :swear

Thats funny george. Im sure you have seen all kinds of things at the MC shop.

Re: i have another ???? air leak around gas cap

Posted: Fri Feb 27, 2009 7:28 pm
by yamaha_george
Funny ? it is now years later but when you some whinning dumb *ss kicking off that the bike doesn't run, who needs it when the fool brought it on him self