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Carb Overflow

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Not sure if it is normal or I have a float sticking on my 400. It doesn't drain any gas when idling or riding around on both wheels but according to my riding partner when I am riding a wheelie it is pouring gas out of my drain hose. I can't tell for sure since I am busy riding a wheelie at the time. :cry: It doesn't flood or anything when I shut it down and leave the gas on, just when I drop it I have to clear it out a little with the decomp but it usually fires right back up after a couple decomp in kicks.

So is this a normal thing or do I have a float sticking? I usually ride about 30 to 50 feet at a time since I am still working on changing gears while still up. Got a little to far back today and my back is hurting from all the dirt ground into it, OUCH!!! :cry:

Thanks for the help.

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when i ride big wheelies sometimes it come sout the overflow tube. I havent had any problems with it flooding or anything like that.

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Think about what the fuel level and the float are doing inside the float bowl when you're riding a wheelie. The fuel moves toward the back of the bowl and the float drops, letting in more fuel. When the level in the bowl reaches overflow, it runs out. You might minimize it by setting the max float drop to 19mm if you haven't already, as the factory setting of 25mm or so is way too much.

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Prior to limiting the float max drop I couldn't ride balance point for any length of time without it loading up and spluttering. After doing the adjustment it stays crisp at balance point, but I'm told by people that follow that the smell of fuel is still present.

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If the bike runs fine then I wouldnt worry about it. When you're doing monos, think about what angle the carb is at and there's a good chance with any bike that you'll get a bit of overflow. Check your float level though, it should be 15mm, I had my XR400 set to this and never had any problems. Good luck.

Mark.

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To clarify, the 15mm figure that Mark talks about is the float "minimum" drop setting. It's actually 14.5mm per the manual.

Check your float level though, it should be 15mm, I had my XR400 set to this and never had any problems. Good luck.

Mark.

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