Reading This May Solve Your Leaking Carburetor Float Needle Valve And Seat Problems

[zoro]

Originally Posted by new rider girl

I left the gas valve open on my bike and found i have gas going into my spark plugs and someone told me to come to this form said I may get some help i took the plugs out and let it air out for about five days i know along time but could not get back to it until today and i changed my oil due to the gas getting in it and replace my plugs my bike still would not start so I took the plugs back out and they smelled of gas again and when I turned the bike over gas came out of the plug holes this is my first bike and i would like to ride it soon how do I find the float valve to see if that is the problem

Hi NRG, 55s fast enough to HURT, and too slow to slide out! Bummer! Hope your not banged up too bad OK,here we go! Gas in the head first.When the bike went down,did any damage occure to the tank at or near the petcock?How about the carbs?Dirt,mud,debris or any thing else come into contact with the carbs or the tank?Did the bike slide to a stop,or did it impact something and take a hard flip? The Float valves are located inside the float bowls on the bottom of each carb.Does that bike have a vacuum operated petcock? Im going to post this to see if your still online....Nope.Are you tooled up enough to pull and dismantle those carbs?

[zoro]

Originally Posted by 07Ninja250

My bike runs fine, with the exception of some decel popping, which I'm still chasing.

But I did have something strange happen one day while trying to synch the carbs.
With the bike not running, I took the tank off and ran some fuel lines from the tank (sitting on the work bench) to the carb lines. Petcock set to "ON". One fuel line, one vacuum line.

Out of curiosity, I removed the fuel tubing from the petcock and held it up, and watched the fuel slowly drain down the tubing and into the carb. It just kept going and going. I thought the float valves would eventually stop it, but it just kept going. I added fuel to the line, and that too flowed right into the carb.

I guess I don't have overflows on these carbs, because all that gas ended up in my crankcase.

I don't get fuel in the crankcase with the bike assembled like normal (tank on, normal fuel lines connected). But any additional fuel pressure coming into the carb (from a long section of tubing, full of fuel, held up) apparently makes its way right past the float valves.

I had to dump a pan full of brand new Mobil 1 because of this.

Is this normal, or do I need to install new float valves? I can only assume that if they get any worse, they'll start allowing too much gas into the carb at all times.

Any thoughts? '96 Yamaha Virago 750

Does your bike have a vacuum operated petcock? If so,thats your problem, no fuel should flow with the petcock "ON".Thats the position to use when removing the tank.

[Jeff.saunders]

While dirt is one of the main causes, there are several other issues.

Inside the needle is a spring. After 20+ years of having the float press up on it, the spring weakens and stops the needle from effectively sealing against the seat. Additionally, gasoline deposits work their way into the inside of the float needle - and those crusty fuel deposits interfer with the spring.

On many of the needles, you will see a ring around the tapered tip - this is a wear mark - once that mark appears, it's time to replace the needle (and often the seat).

[zoro]

Inertial forces to the moving parts in the carbs after the sudden impact of a crash can destroy internal parts,even though out ward appearance may look fine. Those float needles are delicate and use a bendable metal tang for adjustment. These could easily have been damaged in the wipe out. As well as many other parts all over the bike and engine.

[07Ninja250]

Originally Posted by zoro

Does your bike have a vacuum operated petcock? If so,thats your problem, no fuel should flow with the petcock "ON".Thats the position to use when removing the tank.

I ran a vacuum line to the tank so that everything would act normally while I worked on the bike. The petcock works perfectly, it's something I check periodically.

[zoro]

If the petcock is good,then its time to pull the carbs and inspect the float assemblies in each float bowl.Once the carbs are removed,and before the bowls are removed,you can conduct a bench test to determine exactly which carb(s)is leaking fuel into the crankcase.Using a long fuel line(3-6 feet)and a catch pan or bucket,hook the carbs back up to the tank and turn the petcock to PRI,and while holding the carbs over the pan,watch closely to determine which carb(s)is leaking.Keep the carbs level and in running position while conducting this test.And most importantly!!! Be Careful Working With That Gas!!! Do Not Do This In A Closed Garage!!! Let us know whats up! Good Luck!

[yorke]

I have an 06 vulcan 500, a few days ago it fell on the right side. Now when I start the bike and lean to the right the engine revs higher, and when i lean to the left the engine slows down. Could it be a problem with my carburetor floats? and how would I fix that?

[Carphunter]

looks like this is the perfect read for my f5 350 which is ****ing out too much gas when it sits in the garage.

[Airwolf7477]

I just got my gpz900 out of the shop road it 23 miles got home it started leaking fuel out of the carbs on the backside where the airbox is. Me and the mech figured it out I feel so dumb I looked in the tank, and whoever had painted the tank got some inside we dumped all the fuel out saw all kinds of kinds of junk from paint strings floating around. So he is cleaning the carbs out now the needle got stuck and all 4 carbs were leaking fuel I took the tank to be blasted inside and out then going to coat it with red kote then repaint it. That is the only way your going to stop this from happening again. I am going to put a inline filter on it but going to make sure the fuel tank is cleaned out. It is a total headache time, and money this is my first bike 1984 gpz900 I hope I get to the point where things well be ok .thanks guys this group is amazing.