big big fuel leak please help

Message

rhinox · #1 Unread post by **rhinox** » Tue Apr 08, 2008 5:29 am

hi i have a 82 yamaha maxim xs400 that iam having a big problem with the bike starts and sounds like nothing seems to be wrong inside the motor but outside is a diffrent story after the bike starts it starts to leak fuel and i mean alot lol so i looked around to find out where all of the gas was coming from and its come out of the crankcase breather me my self i have never seen gas pour out of the crank breather iam thinking that iam going to have to rebuild the motor but may be this has happend to someone eles and may be a quick fix any suggestions or ideas to what could be the problem iam all ears thanks so much

Tue Apr 08, 2008 6:22 am

Wait... fuel is pouring out of the crankcase breather? Are you sure it's not the carb overflow tube? The crankcase breather should be going back into your airbox or through some kind of filter.

If gas is coming out of there DO NOT START YOUR BIKE. It means that gas has gone from the tank, through the carbs into the cylinder and is now in your oil. Thinned out oil is the devil for bikes.

Sounds like you'll need to clean the carbs and set the float bowl height and maybe rebuild the petcock. Check to see if any fuel is coming out when the petcock is turned off. If it only has on pri and reserve, then check for gas in the vaccum tube.

rhinox · #3 Unread post by **rhinox** » Tue Apr 08, 2008 6:38 am

yes its hard to belive that fuel is come for the crank breather i have cleaned the carrbs but i couldnt see where or how to adjusts the float hight if you know how please let me know thanks

rhinox · #4 Unread post by **rhinox** » Tue Apr 08, 2008 6:39 am

iam up try any thing also thinking about draning the oil to see what it looks like

Tue Apr 08, 2008 6:45 am

Check a service manual. There's typically a piece of metal on the floats that you can bend to adjust height.

As for the oil. It goes without saying that if there's gas in there that you need to change it, flush it, and replace the filter before running it again.. AFTER you fix this problem of fuel getting down there in the first place

rhinox · #6 Unread post by **rhinox** » Tue Apr 08, 2008 6:52 am

but how does the fuel get down there i mean that much fuel i mean maybe if i was giving full gas but its idleing and if the floats where set to high wouldnt it come out the air filter the only thing that i can think of is that the rings or the vale seals are bad

rhinox · #7 Unread post by **rhinox** » Tue Apr 08, 2008 6:54 am

or maybe i should try just to get new carrbs

MrShake · #8 Unread post by **MrShake** » Tue Apr 08, 2008 7:31 am

Don't bother with new carbs, a good cleaning will fix yours right up.

Whats happening is that fuel isn't being stopped in the float bowls (probably a suck float needle) and its overflowing into the carb passages, into your air box, through the vent hose and into the crank case. At least thats my assumption. CLEAN THOSE CARBS!

rhinox · #9 Unread post by **rhinox** » Tue Apr 08, 2008 7:55 am

i just tryed adjusting the float hight and i think it going to work i drained the oil and it was mostley all gas and last week i changed it so i put new oil in and left it a little bit low so i could tell if it was doing it again and hopefuly it will not fill up with gas again and then iam going to change the oil again

rhinox · #10 Unread post by **rhinox** » Tue Apr 08, 2008 9:43 am

thank you every one its fixed it was the floats in the carrbs the oil is looking nice and no more gas is in the oil or coming out the crank breather thanks guys you all are great