Carb just dumping gas out??? Help

[steve lemley]

Okay, I took the carb off my 99 wr400 and installed the zip ty screw. I took the bowl off and the top to inspect everything and note the current jetting set up for future reference. I put it back together and turned the gas on and it was just dumping gas out the bottom bowl overflow line. So thinking the float was stuck, I undid the bowl and made sure it wasent. Tried it again and the same thing so i took it off again and noticed that the float looked to be set a little low so I adjusted it up and tried again. I thaught it was fine and rode it for a whole day with no sputtering or flooding and at the end of the day it was sitting in the garage and i came out to get a beer ? and there was a 3 foot ring of gas under the bike. Its doing it again. I have to take the carb apart this weekend anyway to install the jets for the optopus mod and wanted to ask everyones advice. Did i adjust the float better but just not up high enough? I blew carb cleaner threw the needle/seat area and made sure there was nothing in there, I inspected the needle for wear and it looks brand new whats up??? HELP!!! Thanks.

[MattF]

I had the same problem. I replaced the needle valve even though mine looked alright... problem fixed.

[ArizonaThumper]

check the o ring on the seat

[SJMC_DON]

Yeah those float valves can be touchy, maybe your o-ring is gone altogether?

[steve lemley]

how though i havent taken the seat out to cause it to all the sudden go bad?

[steve lemley]

The dealer wants $45.00 for the needle, seat kit. is that right??? Do you think I could just have it adjusted to low still???

[Dan_Lorenze]

It's happened to me a couple of times before, usually banging on the carb gets the valve to fix itself.

[steve lemley]

Thats if the float is sticking but I dont think thats the problem on this one anyone else have an answer on similar issues and or the proper way to adjust the float??? Thanks for the advice so far guys

[MattF]

When mine was leaking, either riding the bike or banging on the carb seemed to fix it for awhile. Eventually I just had to replace the needle valve. yamaha.motogrid.com has the assembly for about $35.

[new2blu]

I have heard in other gas engines that gas can get inside of the float and cause it to sink a little causing an overlyfull fuel bowl. To check for gas inside of the float remove the float and shake it close to your ear (in a quite area). If it has leaked you should hear a liquid (gas) shaking around in the float. Hope this helps.

[mudhog735]

check your float level with a small ruler. (mm) i would do that before you buy a needle and seat. also make sure there are no (very small) rust particles in your gas. good luck.

[steve lemley]

mudhog, you said to check with a ruler, is there a desired method of measurement when setting the bowl and if so what is it?

Mattf thanks for the link ill check on the price and get one just in case!!

New 2blu, Thanks for the advice, I checked the float for that when i dropped the bowl and its okay.

[potus7640]

Steve,

I just made the same exact mod on the same exact bike and have the same exact problem, will be watching this thread closely for advice and results. I'll try the same fixes suggested to you and we'll see what happens.

[ArizonaThumper]

how though i havent taken the seat out to cause it to all the sudden go bad?

Your neddle and seat could be good, just pull the seat out and look at the o ring, it will dry rot over time causing fuel to leak around the outside of the seat. A new o ring is only a few $ vs. $45 for the whole kit. It is easy to check. Just check it and stop wasting time and fuel, you know a gallon of gas is pricy these days, you could be riding a extra few miles for the fuel you are dumping. CHECK THE O RING!!!!!!

[Moto5]

I agree with Dan, tapping on it with a plastic mallet should do the trick.

[Kepy]

Your neddle and seat could be good, just pull the seat out and look at the o ring, it will dry rot over time causing fuel to leak around the outside of the seat. A new o ring is only a few $ vs. $45 for the whole kit. It is easy to check. Just check it and stop wasting time and fuel, you know a gallon of gas is pricy these days, you could be riding a extra few miles for the fuel you are dumping. CHECK THE O RING!!!!!!

agree ! check the o ring. I've even lost it by screwing on the carb, but fortunately I've found it in near of my bike quite quicky ?

[steve lemley]

Third times a charm... I took it apart, played with the o ring and reset the float to 9mm off the gasket base and all is well on the floor of my garage now. Probley just a chunk of junk in there. Thanks for the advice guys.

[donga]

Had the same issue, cleaned the carb, put it back together and disappeared I think tapping the carb / trying to get needle to seat might be a reasonable start before blowing $45.

[Poway1464]

Also clean the housing of the float valve. I used Q-tips and brass cleaner and polished it up. Then cleaned real good to make sure I didn't leave anything behind. Makes it nice and slippery for a good seat.

[YamahaWR450FMike]

Okay, I took the carb off my 99 wr400 and installed the zip ty screw. I took the bowl off and the top to inspect everything and note the current jetting set up for future reference. I put it back together and turned the gas on and it was just dumping gas out the bottom bowl overflow line. So thinking the float was stuck, I undid the bowl and made sure it wasent. Tried it again and the same thing so i took it off again and noticed that the float looked to be set a little low so I adjusted it up and tried again. I thaught it was fine and rode it for a whole day with no sputtering or flooding and at the end of the day it was sitting in the garage and i came out to get a beer and there was a 3 foot ring of gas under the bike. Its doing it again. I have to take the carb apart this weekend anyway to install the jets for the optopus mod and wanted to ask everyones advice. Did i adjust the float better but just not up high enough? I blew carb cleaner threw the needle/seat area and made sure there was nothing in there, I inspected the needle for wear and it looks brand new whats up??? HELP!!! Thanks.

just the slightest speck of dust will cause this. been there done that. make sure the seat and rubber is very very clean.