Leaking Gas

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yojoego

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Aug 31, 2010
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Forks, WA
Hey I just bought a 96 vmax last weekend, I got it for a great price so I couldn't say no. I noticed that it chugs down at lower RPM especially when starting out. I also noticed that it is leaking gas out of the exhaust pipe. Seems like a fouled plug to me but I have to wait till morning to go and buy a socket. Is it 18mm? And does anyone have any other ideas why this might be happening? Oh an one more thing, it gets terrible gas milage. I went about 70 miles and had to refuel.
 
Sounds like you have one cylinder that is not firing, so it's either car related or electrical on one cylinder.

Easy enough to check, when you get a socket - 18mm is good - pull the plugs, check condition, check each cylinder for spark, if good than carb related.

Mike
 
I know EXACTLY what your problem is - been there, done that.

Check inside your fuel tank with a bright light, I bet you will find it's rusty.

There is only ONE cure: remove the fuel tank and either replace it, or treat it with something like Kreem or similar.

Then replace your fuel filter, clean and blow (with compressed air) all fuel lines, clean and blow the fuel pump, and I'm afraid you will also need to remove and clean your carbs - any of that rust dust will stop your needle valves from sealing, so the fuel keeps running into the cylinders (and the oil), flooding everything (runs like crap) and eventually seeping out of the exghaust pipes.

There are threads here with full instructions (and pictures) on how to do all of the above.
 
50 miles out of a tank!!!! And I thought Toxic got bad mileage:bang head:. Sounds to me like you have a stuck float or a stuck diaphram in one or more of the carbs. I am just praying you didn't wash out a cylinder wall.
 
I don't think it's a bad cyclinder the bike runs awesomone still. I will start the project next month when the weather goes bad of cleaning out the carbs and the fuel lines. Aside from a compression test, is there another sign of a bad cylinder?
 
I don't think it's a bad cyclinder the bike runs awesomone still. I will start the project next month when the weather goes bad of cleaning out the carbs and the fuel lines. Aside from a compression test, is there another sign of a bad cylinder?

You can also perform a leak down test as well. The compression test indicates a piston/ring/cylinder wall issue while the leak down test looks at the valve guides/seats as well.
 
ALSO , PULL OUT THE AIR FILTER , MAYBE ITS 3/4 OF THE WAY PLUGGED ! .. :confused2: .. THAT WILL MAKE IT RUN RICH ALSO !
 
So will that explain why I'm only getting 50 miles out of one tank of gas?

Absolutely!! I was also getting 50-70 miles per tank with the same problem.

Basically gas keeps seeping through all the time - whenever ignition is on the fuel pump never stops (because the fuel bowls can never be full), and everytime the ignition is off all 4 fuel bowls empty themselves into the cylinders, eventually escaping through the exhaust joints.

Have you looked inside your tank yet?

Another quick and easy test: open the fuel bowl drain screws and collect the gas into a white or transparent recipient - you'll see very easily if you have rust dust in there or not..
 
So I looked at my gas tank and ther isnt that much rust. I only saw rust aroung the spout where the gas goes in. I put some carb cleaner in there and ran it hard, let it sit, ran it hard, let it sit and it starts better now and there isn't any gas coming out the exhaust anymore. I aslo bought som sea foam and Im planning on using that.
 
Sounds good - you prolly just had some stuck needle valves then. When this happens, you can loosen them by tapping the carb bodies with a rubber mallet.

Did you drain your fuel bowls to take a look at deposits? Also, renewing your fuel filter is most probably an excellent idea!
 
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