airbox filling with alot gas after running

[jmatt07]

i have a 99 kat and am installing factory pro jetkit and yosh muffler. when i took the airbox off the carbs it was full of gas and poured everywhere. i was told that one of my floats was stuck so i thought no big deal since i was gonna clean the carbs and put jet kit in. well i got them cleaned and put jet kit in. checked all the floats and the correct a/f and everything. So we start the bike and it runs pretty good and no fuel was leaking so i thought it was good. well a few moments after we shut it off fuel started pouring out of the hose that connects to the bottom of airbox (btw...the airbox was full of gas before bc i found that someone had a plug in the bottom of hose so fuel couldnt drain......????) does anyone have any ideas on what could cause this???? thanks

[poscarguy]

id take it back apart and check the needle valves and the oring inside the port that the needle valve sits in. and in combination with that is your petcock on prime?

[kevin2502000]

An easy test to check the needle/seats is blow through the fuel line with the carbs flipped upside down. No air should pass, if it does they are leaking. Since you have the rack off the bike now recheck the float heights as well.

[Kreylyn]

Plug is supposed to be in the bottom of the airbox to prevent vacuum leak... bike won't run well with it open.

Fill the bowls with fuel and fill the fuel lines (hook it all up and turn on reserve for a min or so) ... blow on the lines (disconnect at the petcock), if air passes... a float is not stopping fuel from flowing/not adjusted right... or a float needle is not seating/sealing for some reason.

Krey

Krey

[jmatt07]

okay thanks guys. i set the float height correct and made sure everything was moving freely and not stuck so maybe its an oring or something? ok so let me make sure im understanding you right (sry kinda new to carbs) put the bike on reserve and start it to get fuel in the bowls and lines and then blow in the line that goes to the carbs and if i can hear air escaping then somethings bad?? do i need to take the airbox off of the carbs? and one more question lol if i do hear air what would need to be replaced?

[Kreylyn]

okay thanks guys. i set the float height correct and made sure everything was moving freely and not stuck so maybe its an oring or something? ok so let me make sure im understanding you right (sry kinda new to carbs) put the bike on reserve and start it to get fuel in the bowls and lines and then blow in the line that goes to the carbs and if i can hear air escaping then somethings bad?? do i need to take the airbox off of the carbs? and one more question lol if i do hear air what would need to be replaced?

Fuel flows from the petcock to the carbs. When the fuel reaches the carbs, it flows into a multi port chamber. This chamber has a fill hole into each of the carb bowls at the bottom of the carbs.

On the other side of those holes, are "float needles" that are attatched to the floats. When the fuel flows into the bowls, the floats will rise because they do exactly what they are called... float. When properly adjusted, the floats rise pushing the needle towards the hole eventually plugging the hole off to prevent more fuel from flowing, and keeping the fuel level correct for operating the bike.

If the floats are not adjusted correctly, then they will either not stop the flow of fuel or they will keep the fuel level too low, not allowing enough to flow and leaning out the bike.

Prime (arrow on the knob pointed towards the back of the bike). This allows fuel to flow without a vacuum applied to the petcock (which happens when it's running). Wait 30 seconds to 1 minute tops. Turn it off of prime to the on position (pointed down). Pull the fuel line at the petcock (everything else should be connected just like you were going to ride, except for the side fairing so you can get to the petcock.) Blow into the fuel line. Your going to apply pressure this way for a moment or 2. Not just a quick "blow". If after a moment you can hear either "bubbles" or you can feel that it's allowing air to pass when you blow... then one of your bowls is not sealing off when they are full of fuel.

What to do about it?...

Well, first... you need to determine which ones are the issue.

Once you know where the issue is, then you need to check again for the float height for that carb. Also double check the float needle is in good condition. Check the float needle seat is clean, and even surface. Make sure nothing is floating around in that bowl that could cause an issue.

Krey

[jmatt07]

okay cool thanks alot for that info. helped me to understand it better. ok im gonna check that out and clean the floats and needles and make sure they are in good shape and recheck float height. I was also reading on here that my oil is probably full of gas by now bc my airbox was full of gas and the air filter was soaked. ill change the oil too and see if that helps. Thanks

[kevin2502000]

When you set your floats did you make sure the assembly was seated into the carb body good and snug? If not it will not be an accurate reading. Kreys trouble shooting is the same as mine only I know you will have to take the carbs off anyways to fix which ever problem you find. I myself like to see whats going on inside. If it is leaking air, you can find out easily by pushing on each float until it seals. This test can be done with the carbs dry, flipped upside down, and the float bowls off. I always use this final test before I put them back together.

[Kreylyn]

When you set your floats did you make sure the assembly was seated into the carb body good and snug? If not it will not be an accurate reading. Kreys trouble shooting is the same as mine only I know you will have to take the carbs off anyways to fix which ever problem you find. I myself like to see whats going on inside. If it is leaking air, you can find out easily by pushing on each float until it seals. This test can be done with the carbs dry, flipped upside down, and the float bowls off. I always use this final test before I put them back together.

+1, definately a good test when the carbs are off.

The "wet" test is a simple way of getting people to understand ... yes, you gotta pull them again, it isn't right. Otherwise they come up with "creative" ways to think around just fixing the issue. (like, seafoam will fix everything right?... )


I tend to do both... as the wet test will verify the float levels are not set too rich as well.

I think it's good to remind people that multiple suggestions on this forum are not "one or the other" suggestions... they ussually are a compliment to each other... in other words... do them all.

Krey

[jmatt07]

thanks guys i appreciate all the help. i will def do all of those things to make sure its right. Now when you say that make sure the floats are in the carb body nice and snug how exactly do u mean? i noticed that on mine there was a little play side to side if you wiggled it but i thought it was normal. Also to make sure i measured them correctly you lift up on the float to right where the metal tab touches the metal piece that lifts up the needle correct? im pretty sure im right but i want to be 100%. Also the factory pro kit says to set the float at 14mm and a/f starting at out 2.5 but i printed off a writeup on this forum for installing jetkits and it says floats at 13.5 and a/f at 3 turns out. which should i follow? i also read on here that even if my fuel petcock was stuck on prime one or more of the floats still has to be messed up bc even if prime was on floats shouldnt let fuel pass......correct? Thanks again for all the help.

[Kreylyn]

thanks guys i appreciate all the help. i will def do all of those things to make sure its right. Now when you say that make sure the floats are in the carb body nice and snug how exactly do u mean? i noticed that on mine there was a little play side to side if you wiggled it but i thought it was normal. Also to make sure i measured them correctly you lift up on the float to right where the metal tab touches the metal piece that lifts up the needle correct? im pretty sure im right but i want to be 100%. Also the factory pro kit says to set the float at 14mm and a/f starting at out 2.5 but i printed off a writeup on this forum for installing jetkits and it says floats at 13.5 and a/f at 3 turns out. which should i follow? i also read on here that even if my fuel petcock was stuck on prime one or more of the floats still has to be messed up bc even if prime was on floats shouldnt let fuel pass......correct? Thanks again for all the help.

Float settings are always +/- 1mm, so both suggestions are close enough for a starting point. Jetkits ussually require a little more turn out on the A/F screws for proper idle, so 2.5 would be stock setup, 3 is a good start for a jetkit. You still need to fine tune from there.

Floats should "seat" so there is not really much play for where they plug into the bottom of the carbs. If there is alot of play, you may need to replace the o-rings. They should fit in pretty tight. If not all the way seated, then your float heights are not going to be right.

I prefer to turn the carbs so that the floats just fall into the carb bodies, and measure. Then, put the bowl on, pull it back off... check again. I do this 3 times per bowl... just to make sure something isn't changing the settings on me.

Krey

[kevin2502000]

i also read on here that even if my fuel petcock was stuck on prime one or more of the floats still has to be messed up bc even if prime was on floats shouldnt let fuel pass......correct? Thanks again for all the help.

That is correct, a proper functioning carb will not let fuel flow past the seat and overflow. I run mine all the time in pri with no dire consequences, it's more of a cautionary thing but I would prefer to know if something isn't right.

[jmatt07]

ok cool thanks guys. im thinking now that i set the floats wrong because i just lifted it with my finger till it barely touched the other metal piece but im pretty sure if i tilt the carbs and let the floats just fall out then measure it will be different. also last time i measured in centimeters bc i didnt have a millimeter ruler and tried to get it close so that probably has it off too. ill take the floats off and the seat out and clean everything real good. i bought a new air filter bc the old one has been soaked in gas about 3 times but im afraid of soaking the new one but at the same time im wondering if it will run better with the new filter on it....... also gonna change the oil bc its prolly full of gas but again im scared i will waste the whole oil change if it just floods with gas again.....

[kevin2502000]

Walmart sells mm/cm rulers for like 1$. The float needs to be just LIGHTLY resting on the the float needle not compressing it. It does take attention and a light hand to do it correctly.

[jmatt07]

just an update on whats goin on. today i did that test and blew on the lines and the air DID pass so something was messed up. i took the floats out and took the needles and seats out. the orings on the seats were pretty messed up (dry and cracked) so i replaced those as well as the orings on the emulsion tubes bc they were cracked also. i did the air test with the carbs off after i put it back together and air did NOT pass! so hopefully.......the problem is fixed. we drained the oil and it was more like 75% gas and 25% oil it was as thin as water. im going to change oil tomorrow. would u guys suggest changing the oil in like 50 miles or so or should i put seafoam or something like that in with this oil change and then change it in 50??